Provided by: remind_05.00.02-1_amd64 bug

NAME

       remind - a sophisticated reminder service

SYNOPSIS

       remind [options] filename [date] [*rep] [time]

DESCRIPTION

       Remind reads the supplied filename and executes the commands found in it.  The commands are used to issue
       reminders and alarms.  Each reminder or alarm can consist of a message sent  to  standard  output,  or  a
       program to be executed.

       If filename is specified as a single dash '-', then Remind takes its input from standard input.

       If  filename  happens  to  be a directory rather than a plain file, then Remind reads all of the files in
       that directory that match the pattern "*.rem".  The files are read in sorted order; the  sort  order  may
       depend on your locale, but should match the sort order used by the shell to expand "*.rem".

       Remind  reads  its files starting from the beginning to the end, or until it encounters a line whose sole
       content is "__EOF__" (without the quotes.)  Anything after the __EOF__ marker is completely ignored.

OPTIONS

       Remind has a slew of options.  If you're new to the program, ignore them for now and skip to the  section
       "REMINDER FILES".

       -n     The  -n  option  causes  Remind to print the next occurrence of each reminder in a simple calendar
              format.  You can sort this by date by piping the output through sort(1).  Note that the -n  option
              causes any -g option to be ignored and also implicitly enables the -o option.

       -j[n]  Runs  Remind  in  "purge"  mode  to  get rid of expired reminders.  See the section PURGE MODE for
              details.

       -r     The -r option disables RUN directives and the shell() function.

       -c[flags]n
              The -c option causes Remind to produce a calendar that is sent to standard output.  If you  supply
              a  number  n, then a calendar will be generated for n months, starting with the current month.  By
              default, a calendar for only the current month is produced.  This option implicitly enables the -o
              option.

              You can precede n (if any) with a set of flags.  The flags are as follows:

              '+'    causes a calendar for n weeks to be produced.

              'a'    causes  Remind  to display reminders on the calendar on the day they actually occur as well
                     as on any preceding days specified by the reminder's delta.  This  also  causes  Remind  to
                     include  text  outside %"...%" sequences that would otherwise be removed (though the actual
                     %" markers themselves are removed.)

              'l'    causes Remind to use VT100 line-drawing characters to draw the  calendar.   The  characters
                     are hard-coded and will only work on terminals that emulate the VT00 line-drawing character
                     set.

              'u'    is similar to 'l', but causes Remind to use UNICODE line-drawing  characters  to  draw  the
                     calendar.   The  characters  are hard-coded and will only work on terminals that are set to
                     UTF-8 character encoding.  This flag also enables the use of  the  UNICODE  "left-to-right"
                     mark  that  can  fix  up  formatting  problems with right-to-left languages in the calendar
                     display.

              'c'    causes Remind to use VT100 escape sequences to approximate SPECIAL COLOR  reminders.   Note
                     that  this  flag  is  kept  for  backwards-compatibility;  you should use the -@[n][,m][,b]
                     command-line option instead.

       -@[n][,m][,b]
              Tells Remind to approximate SPECIAL COLOR and SHADE reminders using VT100 escape  sequences.   The
              approximation  is  (of  necessity)  very  coarse, because the VT100 only has eight different color
              sequences, each with one of two brightnesses.  A color component greater  than  64  is  considered
              "on",  and  if  any  of  the  three  color components is greater than 128, the color is considered
              "bright".

              If you supply the optional numeric parameters, the have the following meanings:  n=0 tells  Remind
              to  use the standard 16 VT100 colors.  n=1 tells it to use an extended 256-color palette supported
              by many terminal emulators such as xterm.  And n=2 tells it to use escape sequences  that  support
              true 24-bit colors, again supported by many terminal emulators such as xterm.

              If the optional m parameter is supplied following a comma, then m=0 tells Remind that the terminal
              background is dark, and Remind will brighten up dark colors to make them visible.   If  m=1,  then
              Remind  assumes  the  terminal  background  is light and it will darken bright colors to make them
              visible.  If m is specified as 2, then Remind does not perform any adjustments, and some reminders
              may  be  hard or impossible to see if the color is too close to the terminal background color.  If
              you supply the letter t rather than a number, then Remind attempts to guess the  background  color
              of the terminal, even if stdout is not a terminal.

              On  startup,  if  the  standard output is a terminal, Remind attempts to determine if the terminal
              background is dark or light by sending a special  escape  sequence  to  determine  the  background
              color.  The m parameter can override this check (or force it if m is given as t.)

              If the optional b parameter is supplied following a comma, then b=0 tells Remind to ignore SPECIAL
              SHADE reminders (the default) and b=1 tells Remind to respect SPECIAL SHADE reminders by  emitting
              VT100  escape  codes  to color the background of the calendar cell.  Note that SHADE does not work
              well unless you are using the extended 256-color palette (n=1) or the true  24-bit  colors  (n=2).
              Note  that for calendar cells that are shaded, the clamping mechanism described earlier for m=0 or
              m=1 is skipped; it is assumed that if you set both the foreground color  of  a  reminder  and  the
              background color of a cell, then you know what you are doing.

       -wcol[,pad[,spc]]]
              The  -w  option  specifies the output width, padding and spacing of the formatted calendar output.
              Col specifies the number of columns in the  output  device.   If  col  is  not  specified,  or  is
              specified  as 0, it defaults to the larger of 71 or the actual width of your terminal, or to 80 if
              standard output is not a terminal.  If col is specified as the letter t, then Remind  attempts  to
              get  the width of the /dev/tty terminal device.  This is useful, for example, if you pipe calendar
              output into less; even though standard output is a  pipe,  you  want  the  calendar  to  be  sized
              correctly for your terminal window:

                      remind -c -wt .reminders | less

              Note  that  the  value  of  col  is  also  used  to  set  the system variable $FormWidth, which is
              initialized to col - 8.  See "SYSTEM VARIABLES" for details.

              Pad specifies how many lines to use to "pad" empty calendar boxes.  This defaults to  5.   If  you
              have  many  reminders  on certain days that make your calendar too large to fit on a page, you can
              try reducing pad to make the empty boxes smaller.  Spc specifies how many  blank  lines  to  leave
              between the day number and the first reminder entry.  It defaults to 1.

              Any  of col, pad or spc can be omitted, providing you provide the correct number of commas.  Don't
              use any spaces in the option.

       -s[a]n The -s option is very similar to the -c option, except that the output calendar is not  formatted.
              It  is  listed  in  a  "simple  format" that can be used as input for more sophisticated calendar-
              drawing programs.  If n starts with "+", then it is interpreted as a number of weeks.  This option
              also implicitly enables the -o option.

              If  you immediately follow the s with the letter a, then Remind displays reminders on the calendar
              on the day they actually occur as well as on any preceding days specified by the reminder's delta.

       -p[a][p][p][q]n
              The -p option is very similar to the  -s  option,  except  that  the  output  contains  additional
              information  for use by the Rem2PS program, which creates a PostScript calendar, and various other
              back-end programs.  For this option, n cannot start with "+"; it must specify a number of  months.
              The format of the -p output is described in the rem2ps(1) man page.  If you immediately follow the
              p with the letter a, then Remind displays reminders on the calendar on the day they actually occur
              as  well  as  on  any  preceding days specified by the reminder's delta.  If you follow the p with
              another p, then Remind uses a  more  comprehensive  JSON-based  format  rather  than  the  "simple
              calendar"  format.  This format is also documented in the rem2ps(1) man page.  Finally, if you use
              three p's, as in -ppp, then Remind uses a pure JSON format, again documented in rem2ps(1).  If you
              include a q letter with this option, then the normal calendar-mode substitution filter is disabled
              and the %"...%" sequences are preserved in the output.

              The -p, -pp and -ppp options implicitly enable the -o option.

              Note that the -pp or -ppp options also enable the -l option.

       -l     If you use the -l option in conjunction  with  the  -p  option,  then  Remind  outputs  additional
              information  for  back-end programs such as rem2ps.  This additional information lets the back-end
              programs correlate a reminder with the source file and line number that produced it.

       -m     The -m option causes the -c or -p options to produce a  calendar  whose  first  column  is  Monday
              rather than Sunday.  (This conforms to the international standard.)

       -v     The  -v option makes the output of Remind slightly more verbose.  Currently, this causes Remind to
              echo a bad line in case of an error, and to print a security message if a script tests the $RunOff
              system variable.

       -o     The  -o option causes Remind to ignore all ONCE directives.  Note that ONCE is also ignored if any
              of the -c, -n, -p, or -s options is used, if a repetition factor *n is used, or if  a  date  other
              than today's date is specified on the command-line.

       -t     The -t option causes Remind to trigger all non-expired reminders, regardless of the delta supplied
              for each reminder.

       -tn    If you supply a number n after the -t option, then Remind pretends that echo  REM  command  has  a
              delta of ++n, regardless of any existing delta.

       -tz    If  you  supply  the  letter z after the -t option, then Remind sets all REM statements' deltas to
              zero, regardless of the value supplied in the REM statement itself.  In effect, this disables  all
              deltas of the form +n and ++n.

       -tt[n] The  -tt  option causes Remind to assume a default delta of n minutes for all timed reminders.  If
              -tt is given with no n, a default delta of 5 minutes is used.

       -h     The -h option ("hush...") suppresses certain warning and information messages.  In particular,  if
              no reminders are triggered, this mode produces no output.

       -a     The -a option causes Remind not to immediately trigger timed reminders that trigger on the current
              day.  It also causes Remind not to place timed reminders in a calendar.  If you supply two or more
              -a  options, then Remind will trigger timed reminders that are in the future, but will not trigger
              timed reminders whose time has passed.  (Regardless of how many -a options you supply, Remind will
              not include timed reminders in the calendar if at least one -a option is used.)

       -q     The -q option causes Remind not to queue timed reminders for later execution.

       -f     The  -f  option causes Remind to remain in the foreground when processing queued reminders, rather
              than forking off a background process to handle them.

       -e     The -e option diverts error messages (normally sent to the standard error stream) to the  standard
              output stream.

       -dchars
              The -d option enables certain debugging modes.  The chars specify which modes to enable:

         e      Echo all input lines

         x      Trace all expression evaluation

         t      Display all trigger date computation

         v      Dump the variable table after execution of the reminder script

         l      Echo lines when displaying error messages

         f      Trace the reading of reminder files

         s      Trace  expression parsing and display the internal expression node tree.  This is unlikely to be
                useful unless you are working on Remind's expression evaluation engine.

       -g[a|d[a|d[a|d[a|d]]]]
              Normally, reminders are issued in the order in which they are encountered in the reminder  script.
              The -g option cause Remind to sort reminders by date and time prior to issuing them.  The optional
              a and d characters specify the sort order  (ascending  or  descending)  for  the  date,  time  and
              priority fields.  See the section "SORTING REMINDERS" for more information.

              Note that -g is ignored if you use the -n option.

       -b[n]  Set  the  time format for the calendar and simple-calendar outputs.  N can range from 0 to 2, with
              the default 0.  A value of 0 causes times to be inserted in  12-hour  (am/pm)  format.   1  causes
              times  to  be  inserted  in 24-hour format, and 2 inhibits the automatic insertion of times in the
              calendar output.

       -x[n]  Sets the iteration limit for the SATISFY clause of a REM command.  Defaults to 1000.

       -kcmd  Instead of simply printing MSG-type reminders, this causes them to be passed to the specific  cmd.
              You  must  use  '%s'  where  you  want  the body to appear, and may need to enclose this option in
              quotes.  Note that all shell characters in the body of the reminder are escaped with a  backslash,
              and  the  entire  body  of  the  reminder  is  passed as a single argument.  Note that this option
              overrides the -r option and the RUN OFF command.

              As an example, suppose you have an X Window program called xmessage that  pops  up  a  window  and
              displays its invocation arguments.  You could use:

                        remind '-kxmessage %s &' ...

              to have all of your MSG-type reminders processed using xmessage.

              A word of warning: It is very easy to spawn dozens of xmessage processes with the above technique.
              So be very careful.  Because all shell and whitespace characters  are  escaped,  the  program  you
              execute with the -k option must be prepared to handle the entire message as a single argument.

              If  you  follow  the  -k  option  with  a  colon, then the command is applied only to queued timed
              reminders.  Normal reminders are handled as usual.  In the  above  example,  if  you  want  normal
              reminders  to  simply  be  displayed as usual, but queued reminders to be sent to notify-send, you
              could use:

                        remind '-k:notify-send %s &' ...

              You use both -kcmd1 and -k:cmd2 to use different commands for queued versus non-queued reminders.

       -z[n] Runs Remind in "daemon mode".  If n
              is supplied, it specifies how often (in minutes) Remind should wake up to check  if  the  reminder
              script  has  been changed.  N defaults to 1, and can range from 1 to 60.  Note that the use of the
              -z option also enables the -f option.

              If Remind is compiled on a system that supports inotify(7), then if the reminder  script  supplied
              on  the  command-line is actually a directory, Remind additionally checks if all files within that
              directory have been modified since startup.

              If you supply the option -zj, Remind  runs  in  a  special  mode  called  server  mode.   This  is
              documented  in  the  tkremind  man  page; see tkremind(1).  The older server mode option -z0 still
              works, but is deprecated; it uses an ad-hoc method to communicate  with  the  client  rather  than
              using JSON to communicate with the client.

       -uname Runs  Remind  with  the uid and gid of the user specified by name.  The option changes the uid and
              gid as described, and sets the environment variables HOME, SHELL and USER to the  home  directory,
              shell,  and  user name, respectively, of the specified user.  LOGNAME is also set to the specified
              user name.  This option is meant for use in shell scripts that mail reminders to all users.   Note
              that  as  of  Remind  3.00.17,  using -u implies -r -- the RUN directive and shell() functions are
              disabled.  However, if you prefix name with a +-sign, then RUN and shell() are not disabled.  That
              is,  -uwhatever  switches  the user to whatever and disables RUN, whereas -u+whatever switches the
              user to whatever but leaves RUN enabled.

              Non-root users can also use the -u option.  However, in this case, it only changes the environment
              variables as described above.  It does not change the effective uid or gid.

       -+username
              Causes  Remind  to  trust files owned by the user username.  Normally, if Remind reads a file that
              you do not own, it disables RUN and the shell() function.  This option causes  it  to  also  trust
              files  owned  by  username.   You  can supply multiple -+ options to trust multiple users, up to a
              limit of 20 trusted users.

       -y     Causes Remind to synthesize a tag for any reminder that lacks a TAG clause.

       -ivar=expr
              Sets the value of the specified var to expr, and preserves var.  Expr  can  be  any  valid  Remind
              expression.   See  the  section "INITIALIZING VARIABLES ON THE COMMAND LINE" for more details.  If
              you omit the =expr part, then var is initialized to 0.  In other words, -ivar is exactly the  same
              as -ivar=0.

       -ifunc(args)=definition
              Allows you to define a function on the command line.

       If  you supply a date on the command line, it must consist of day month year, where day is the day of the
       month, month is at least the first three letters of the English name of the month, and  year  is  a  year
       (all 4 digits) from 1990 to about 2075.  You can leave out the day, which then defaults to 1.

       If  you do supply a date on the command line, then Remind uses it, rather than the actual system date, as
       its notion of "today."  This lets you create calendars for  future  months,  or  test  to  see  how  your
       reminders  will  be  triggered in the future.  Similarly, you can supply a time to set Remind's notion of
       "now" to a particular time.  Supplying a time on the command line also implicitly enables the  -q  option
       and  disables  the  -z option.  The time may be specified in 24-hour format (eg, 13:20) or common "AM/PM"
       format (1:20pm).

       If you would rather specify the date more succinctly, you can supply it as YYYY-MM-DD or YYYY/MM/DD.  You
       can even supply a date and time on the command line as one argument: YYYY-MM-DD@HH:MM.

       In  addition,  you  can supply a repeat parameter, which has the form *rep.  This causes Remind to be run
       rep times, with the date incrementing on each iteration.  You may have to enclose the parameter in quotes
       to  avoid  shell  expansion.   See the subsection "Repeated Execution" in the section "CALENDAR MODE" for
       more information.

LONG OPTIONS

       Remind supports the following long options, which are case-sensitive:

       --version The --version option causes Remind to print its version number  to  standard  output  and  then
       exit.

       --max-execution-time=n
              Limit  the  total  execution time (as measured by the wall clock) to n seconds.  This is useful if
              Remind is invoked on potentially-untrustworthy files that could attempt to use a lot of resources.
              Note  that  the limit n is approximate and Remind might execute for one or two more seconds before
              it is killed.  If n is specified as zero, then no limit is applied, just as if the option had  not
              been used at all.

       If  a  limit  is applied, it applies only to the foreground run of Remind.  If Remind finishes processing
       the script and then starts handling queued reminders, the time limit is reset to no limit.

REMINDER FILES

       Remind uses scripts to control its operation.  You can use any text editor capable of creating plain-text
       files  to create a Remind script.  The commands inside a script can range from the very simple and almost
       immediately understandable:

               REM Mar 31 MSG International Transgender Day of Visibility

       to the baroque and obscure:

               REM [date(thisyear, 1, 1) + 180] ++5 OMIT \
               sat sun BEFORE MSG [ord(thisyear-1980)] payment due %b!

       A reminder file consists of commands, with one command per line.  Several lines can  be  continued  using
       the  backslash  character,  as  in  the  above  example.  In this case, all of the concatenated lines are
       treated as a single line by Remind.  Note that if an error occurs, Remind reports the line number of  the
       last line of a continued line.

       Remind  ignores  blank  lines,  and  lines  beginning  with  the  '#' or ';' characters.  You can use the
       semicolon as a comment character if you wish to pass a Remind script through the C  pre-processor,  which
       interprets the '#' character as the start of a pre-processing directive.

       Note that Remind processes line continuations before anything else.  For example:

            # This is a comment \
            This line is part of the comment because of line continuation \
            and so on.
            REM MSG This line is not ignored (no \ above)

       Remind  is  not  case  sensitive; you can generally use any mixture of upper- or lower-case for commands,
       parameters, invocation options, etc.

THE REM COMMAND

       The most powerful command in a Remind script is the REM command.  This command is responsible for issuing
       reminders.  Its syntax is:

              REM  [ONCE]  [date_spec]  [back]  [delta]  [repeat]  [PRIORITY prio] [SKIP | BEFORE | AFTER] [OMIT
              omit_list] [ADDOMIT] [NOQUEUE]  [OMITFUNC  omit_function]  [AT  time  [tdelta]  [trepeat]]  [SCHED
              sched_function] [WARN warn_function] [UNTIL expiry_date | THROUGH last_date] [SCANFROM scan_date |
              FROM start_date] [DURATION duration] [TAG tag] <MSG | MSF | RUN | CAL | SATISFY | SPECIAL  special
              | PS | PSFILE> body

       The  parts  of  the REM command can be specified in any order, except that the body must come immediately
       after the MSG, RUN, CAL, PS, PSFILE or SATISFY keyword.

       The REM token is optional, providing that the remainder of the command cannot  be  mistaken  for  another
       Remind  command  such  as  OMIT  or  RUN.  The portion of the REM command before the MSG, MSF RUN, CAL or
       SATISFY clause is called a trigger.

       MSG, MSF, RUN, CAL, SPECIAL, PS and PSFILE

       These keywords denote the type of the reminder.  (SATISFY is  more  complicated  and  will  be  explained
       later.)   A  MSG-type  reminder  normally prints a message to the standard output, after passing the body
       through a special substitution filter, described in the section "THE SUBSTITUTION FILTER."   However,  if
       you  have used the -k command-line option, then MSG-type reminders are passed to the appropriate program.
       Note that the options -c, -s, -p and -n disable the -k option.

       Note that you can omit the reminder type, in which case it defaults to MSG.  So you can write:

            6 January Dianne's Birthday

       although this is not recommended.

       The MSF keyword is almost the same as the MSG keyword, except that the reminder is formatted to fit  into
       a  paragraph-like format.  Three system variables control the formatting of MSF-type reminders - they are
       $FirstIndent, $SubsIndent and $FormWidth.  They are discussed in the section "SYSTEM VARIABLES."  The MSF
       keyword  causes  the  spacing of your reminder to be altered - extra spaces are discarded, and two spaces
       are placed after periods and other  characters,  as  specified  by  the  system  variables  $EndSent  and
       $EndSentIg.   Note that if the body of the reminder includes newline characters (placed there with the %_
       sequence), then the newlines are treated as the  beginnings  of  new  paragraphs,  and  the  $FirstIndent
       indentation  is  used  for the next line.  You can use two consecutive newlines to have spaced paragraphs
       emitted from a single reminder body.

       A RUN-type reminder also passes the body through the substitution filter, but then executes the result as
       a system command.  A CAL-type reminder is used only to place entries in the calendar produced when Remind
       is run with the -c, -s or -p options.

       A PS or PSFILE-type reminder is used to pass PostScript code  directly  to  the  printer  when  producing
       PostScript  calendars.   This can be used to shade certain calendar entries (see the psshade() function),
       include graphics in the calendar, or almost any other purpose you can think of.  You should not use these
       types  of  reminders  unless  you  are  an expert PostScript programmer.  The PS and PSFILE reminders are
       ignored unless Remind is run with the -p option.  See  the  section  "More  about  PostScript"  for  more
       details.

       A  SPECIAL-type  reminder  is  used to pass "out-of-band" information from Remind to a calendar-producing
       back-end.  It should be followed by a word indicating the type of special data being passed.  The type of
       a special reminder depends on the back-end.  For the Rem2PS back-end, SPECIAL PostScript is equivalent to
       a PS-type reminder, and SPECIAL PSFile is equivalent to a PSFILE-type reminder.  The body  of  a  SPECIAL
       reminder  is  obviously  dependent  upon the back-end.  A back-end must ignore a SPECIAL that it does not
       recognize.

       DATE SPECIFICATIONS

       A date_spec consists of zero to four parts.  These parts are day (day of month), month (month name), year
       and  weekday.   Month and weekday are the English names of months and weekdays.  At least the first three
       characters must be used.  The following are examples of the various parts of a date_spec:

       day:   1, 22, 31, 14, 3

       month: JANUARY, feb, March, ApR, may, Aug

       year:  1990, 1993, 2030.  The year can range from 1990 to 2075.

       weekday:
              Monday, tue, Wed, THU, Friday, saturday, sundAy

       Note that there can be several weekday components separated by spaces in a date_spec.

       INTERPRETATION OF DATE SPECIFICATIONS

       The following examples show how date specifications are interpreted.

       1. Null date specification - the reminder is triggered every day.  The trigger date for a specific run is
       simply the current system date.  For example:

               REM MSG This is triggered every time Remind runs

       2. Only day present.  The reminder is triggered on the specified day of each month.  The trigger date for
       a particular run is the closest such day to the current system date.  For example:

            REM 1 MSG First of every month.
            REM 31 MSG 31st of every month that has 31 days.

       3. Only month present.  The reminder is triggered every day of the specified month.  Example:

            REM Feb MSG Every day in February

       4.  day and month present.  Examples:

            REM 6 Jan MSG Every 6th of January
            REM Feb 29 MSG Every 29th of February

       5.  Only year present. Example:

            REM 1991 MSG Every day in 1991

       6.  year and day present.  Examples:

            REM 1 1990 MSG 1st of every month in 1990
            REM 1992 23 MSG 23rd of every month in 1992

       7.  year and month present.  Examples:

            REM Feb 1991 MSG Every day in Feb 1991
            REM 1992 September MSG Every day in Sept 1992

       8.  year, month and day present.  Examples:

            REM 8 Jan 1991 MSG 8th January 1991.
            REM 1992 March 9 MSG 9th March 1992.

       9.  weekday only.  Examples:

            REM Sat MSG Every Saturday
            REM Mon Tue Wed Thu Fri MSG Every working day
            REM Monday Wednesday MSG Every Monday and Wednesday

       10.  weekday and day present.  Examples:

            REM Sat 1 MSG First Saturday of every month
            REM Mon Tue Wed Thu Fri 15 \
                 MSG 1st working day on or after 15th of every month

       11.  weekday and month present.  Examples:

            REM Mon March MSG Every Monday in March
            REM Mon Tue Wed Thu Fri Feb MSG Every working day in February

       12.  weekday, month and day present.  Examples:

            REM Mon 1 March MSG First Monday in March
            REM Sat Sun 15 July MSG First Sat or Sun on or after 15 July

       13.  weekday and year present.  Example:

            REM Sat Sun 1991 MSG Every Saturday and Sunday in 1991

       14.  weekday, day and year present.  Examples:

            REM Mon 15 1990 MSG 1st Mon after 15th of every month in 1990
            REM Mon Tue Wed Thu Fri 1 1990 \
                 MSG 1st working day of every month in 1990

       15.  weekday, month and year present.  Example:

            REM Mon Wed 1991 Feb MSG Every Mon and Wed in Feb 1991.

       16.  weekday, day, month and year present.  Example:

            REM Mon Tue Wed Thu Fri 28 Oct 1990 \
                 MSG 1st working day on or after 28 October 1990.

       Note that when both weekday and day are specified,  Remind  chooses  the  first  date  on  or  after  the
       specified  day  that also satisfies the weekday constraint.  It does this by picking the first date on or
       after the specified day that is listed in the list of weekdays.  Thus, a reminder like:

            REM Mon Tue 28 Oct 1990 MSG Hi

       would be issued only on Monday, 29 October, 1990.  It would not be issued on Tuesday, 30  October,  1990,
       since the 29th is the first date to satisfy the weekday constraints.

       SHORT-HAND DATE SPECIFICATIONS

       In addition to spelling out the day, month and year separately, you can specify YYYY-MM-DD or YYYY/MM/DD.
       For example, the following statements are equivalent:

            REM 5 June 2010 MSG Cool!
            REM 2010-06-05  MSG Cool!

       You can also specify a date and time as YYYY-MM-DD@HH:MM.  These statements are equivalent:

            REM 19 Dec 2010 AT 16:45 MSG Hi
            REM 2010-12-19@16:45 MSG Hi

       There's one subtlety with short-hand date specifications:  The following statements are not equivalent:

            REM 19 Dec 2010 AT 16:45 +60 MSG Hi
            REM 2010-12-19@16:45 +60 MSG Hi

       In the second statement, the "+60" is a delta that applies to the date rather than a tdelta that  applies
       to the time.  We recommend explicitly using the AT keyword with timed reminders.

       THE REMIND ALGORITHM

       Remind  uses  the  following  algorithm  to  compute  a  trigger date: Starting from the current date, it
       examines each day, one at a time, until it finds a date that satisfies the date specification, or  proves
       to  itself  that  no such date exists.  (Actually, Remind merely behaves as if it used this algorithm; it
       would be much too slow in practice.  Internally, Remind  uses  much  faster  techniques  to  calculate  a
       trigger date.)  See DETAILS ABOUT TRIGGER COMPUTATION for more information.

       BACKWARD SCANNING

       Sometimes,  it  is  necessary  to  specify a date as being a set amount of time before another date.  For
       example, the last Monday in a given month is computed as the first Monday in  the  next  month,  minus  7
       days.  The back specification in the reminder is used in this case:

            REM Mon 1 -7 MSG Last Monday of every month.

       A  back  is  specified  with  one  or  two  dashes  followed  by  an integer.  This causes Remind to move
       "backwards" from what would normally be the trigger date.  The difference between  --7  and  -7  will  be
       explained when the OMIT keyword is described.

       ADVANCE WARNING

       For some reminders, it is appropriate to receive advance warning of the event.  For example, you may wish
       to be reminded of someone's birthday several days in advance.  The  delta  portion  of  the  REM  command
       achieves  this.   It  is specified as one or two "+" signs followed by a number n.  Again, the difference
       between the "+" and "++" forms will be explained  under  the  OMIT  keyword.   Remind  will  trigger  the
       reminder  on  computed  trigger  date,  as well as on each of the n days before the event.  Here are some
       examples:

            REM 6 Jan +5 MSG Remind me of birthday 5 days in advance.

       The above example would be triggered every 6th of January, as well as the 1st through 5th of January.

       PERIODIC REMINDERS

       We have already seen some built-in mechanisms for certain types of periodic reminders.  For  example,  an
       event occurring every Wednesday could be specified as:

            REM Wed MSG Event!

       However, events that do not repeat daily, weekly, monthly or yearly require another approach.  The repeat
       component of the REM command fills this need.  To use it, you must completely specify a date (year, month
       and  day, and optionally weekday); this is the start date of the repetition period.  The repeat component
       is an asterisk followed by a number specifying the repetition period in days.

       For example, suppose you get paid every second Wednesday, and your last payday was Wednesday, 28 October,
       1992.  You can use:

            REM 28 Oct 1992 *14 MSG Payday

       This  issues  the  reminder  every  14  days, starting from 28 Oct 1992.  You can use delta and back with
       repeat.  Note, however, that the back is used only to compute the starting date; thereafter, the reminder
       repeats with the specified period.  Similarly, if you specify a weekday, it is used only to calculate the
       starting date, and does not affect the repetition period.

       SCANFROM and FROM

       The SCANFROM and FROM keywords are for advanced Remind programmers only, and will  be  explained  in  the
       section "DETAILS ABOUT TRIGGER COMPUTATION" near the end of this manual.  Note that SCANFROM is available
       only in versions of Remind from 03.00.04 up.  FROM is available only from 03.01.00 and later.

       PRIORITY

       The PRIORITY keyword must be followed by a number from 0 to 9999.  It is used in calendar mode  and  when
       sorting  reminders.   If  two  reminders  have  the  same  trigger date and time, then they are sorted by
       priority.  If the PRIORITY keyword is not supplied, a default priority of 5000 is  used.   (This  default
       can  be  changed  by  adjusting the system variable $DefaultPrio.  See the section "SYSTEM VARIABLES" for
       more information.)

       EXPIRY DATES

       Some reminders should be issued periodically for a certain time, but then expire.  For  example,  suppose
       you have a class every Friday, and that your last class is on 11 December 1992.  You can use:

            REM Fri UNTIL 11 Dec 1992 MSG Class today.

       Another  example:  Suppose you have jury duty from 30 November 1992 until 4 December 1992.  The following
       reminder will issue the message every day of your jury duty, as well as 2 days ahead of time:

            REM 1992-11-30 *1 +2 UNTIL 1992-12-04 MSG Jury duty

       Note that the repeat of *1 is necessary; without it, the reminder would be issued  only  on  30  November
       (and the two days preceding.)

       As  a  special  case,  you  can  use  the THROUGH keyword instead of *1 and UNTIL.  The following two REM
       commands are equivalent:

            REM 1992-11-30 *1 +2 UNTIL 1992-12-04 MSG Jury duty

            REM 1992-11-30 +2 THROUGH 1992-12-04 MSG Jury duty

       If you have an expiry date via the use of THROUGH or UNTIL, then Remind will never trigger  the  reminder
       after the expiry date.  For example, if you have this:

               OMIT 2021-01-08
               REM 2021-01-01 THROUGH 2021-01-08 AFTER MSG Test

       the reminder will not be triggered on 2021-01-08, and nor will it be triggered on 2021-01-09; even though
       the AFTER keyword would normally move the 8th's reminder to  the  9th,  the  expiry  date  of  2021-01-08
       overrides that.

       THE ONCE KEYWORD

       Sometimes,  it  is  necessary  to  ensure  that reminders are run only once on a given day.  For example,
       compare the following two reminders:

               REM Fri RUN do_backup
               REM Fri ONCE RUN do_backup

       The first will be run every time you invoke Remind on a Friday, whereas the second will be run  only  the
       first time you invoke Remind on a given Friday.

       If  you  run Remind from your .login script, for example, and log in several times per day, the do_backup
       program in the first reminder will be run each time you log in.  If, however, you use the ONCE keyword in
       the  reminder,  the  Remind checks the last access date of the reminder script.  If it is the same as the
       current date, Remind assumes that it has already been run, and will not issue  reminders  containing  the
       ONCE keyword.

       Note  that  if  you view or edit your reminder script, the last access date will be updated, and the ONCE
       keyword will not operate properly.  You can fix this by setting a timestamp file for Remind to track  the
       last-run  date;  see the documentation of $OnceFile in the SYSTEM VARIABLES section.  If you use standard
       input as your Remind input file, then you must use 0 ONCE keyword to work properly.

       If you start Remind with the -o option, then the ONCE keyword will be ignored and any $OnceFile  will  be
       ignored.

       LOCALLY OMITTING WEEKDAYS

       The  OMIT  portion of the REM command is used to "omit" certain days when counting the delta or back.  It
       is specified using the keyword OMIT followed by a list of weekdays.  Its action is best illustrated  with
       examples:

            REM 1 +1 OMIT Sat Sun MSG Important Event

       This  reminder  is  normally  triggered  on  the  first  of every month, as well as the day preceding it.
       However, if the first of the month falls on a Sunday or Monday, then the reminder is  triggered  starting
       from  the  previous  Friday.   This  is because the delta of +1 does not count Saturday or Sunday when it
       counts backwards from the trigger date to determine how much advance warning to give.

       Contrast this with the use of "++1" in the above command.  In this case, the reminder is triggered on the
       first of each month, as well as the day preceding it.  The omitted days are counted.

            REM 1 -1 OMIT Sat Sun MSG Last working day of month

       Again,  in  the  above example, the back of -1 normally causes the trigger date to be the last day of the
       month.  However, because of the OMIT clause, if the first of the month falls on a Sunday or  Monday,  the
       trigger  date is moved backwards past the weekend to Friday.  (If you have globally omitted holidays, the
       reminder will be moved back past them, also.  See "The OMIT command" for more details.)

       By comparison, if we had used "--1", the reminder would be triggered  on  the  last  day  of  the  month,
       regardless of the OMIT.

       If  you  locally omit weekdays but also have globally-omitted weekdays, then the list of omitted weekdays
       is the union of the two.  Consider this example:

               OMIT Sat Sun
               REM 15 OMIT Fri Sat MSG Whatever

       In the REM command, the effective list of omitted weekdays will be Friday, Saturday and Sunday.

       COMPUTED LOCAL OMITS

       The OMITFUNC phrase of the REM command allows you to supply a function that determines whether or  not  a
       date  is  omitted.   The  function  is passed a single parameter of type DATE, and must return a non-zero
       integer if the date is considered "omitted" and 0 otherwise.  Here's an example:

               FSET _third(x) (day(x) % 3) || \
                              (wkdaynum(x) == 0) || \
                              (wkdaynum(x) == 6)
               REM OMITFUNC _third AFTER MSG Working day divisible by 3

       In the example above, the reminder is triggered every Monday  to  Friday  whose  day-of-month  number  is
       divisible by three.  Here's how it works:

       o      The  OMITFUNC _third portion causes all days for which _third(x) returns non-zero to be considered
              "omitted".  This causes all days whose day-of-month number is  not  a  multiple  of  three  to  be
              omitted.  Note that _third also returns non-zero if the weekday is Sunday or Saturday.

       o      The AFTER keyword causes the reminder to be moved after a block of omitted days.

       The  combination of OMITFUNC and AFTER keyword causes the reminder to be issued on all days whose day-of-
       month number is divisible by three, but not on Saturday or Sunday.

       Note that if you use OMITFUNC, then a local OMIT is ignored as are all global OMITs.  If you want to omit
       specific  weekdays, your omit function will need to test for them specifically.  If you want to take into
       account the global OMIT context, then your omit function will need to test for that explicitly (using the
       isomitted() function.)

       Note  that  an  incorrect  OMITFUNC might cause all days to be considered omitted.  For that reason, when
       Remind searches through omitted days,  it  terminates  the  search  after  the  SATISFY  iteration  limit
       (command-line option -x.)

       ADDING TRIGGER DATES TO THE OMIT CONTEXT

       If  the  ADDOMIT  keyword appears in a REM command, then the trigger date (if one could be calculated) is
       automatically added to the list of global OMITs.

       The command:

               REM ... whatever ... ADDOMIT MSG Foo

       is identical in behaviour to the sequence:

               REM ... whatever ... SATISFY 1
               IF trigvalid()
                   OMIT [trigdate()] MSG Foo
               ENDIF

       TIMED REMINDERS

       Timed reminders are those that have an AT keyword followed by a time and  optional  tdelta  and  trepeat.
       The  time  may  be specified in 24-hour format, with 0:00 representing midnight, 12:00 representing noon,
       and 23:59 representing one minute to midnight.  Alternatively, it may  be  specified  in  common  "AM/PM"
       format;  in this case, the hour must range from 1 to 12.  12:00am represents midnight, 12:00pm represents
       noon, and 11:59pm represents one minute to midnight.  The "am" and "pm" portions are case-insensitive and
       the "m" is optional.

       You  can use either a colon or a period to separate the hours from the minutes.  That is, 13:39 and 13.39
       are equivalent.

       Remind treats timed reminders specially.  If the trigger date for a timed reminder is  the  same  as  the
       current  system  date,  the reminder is queued for later activation.  When Remind has finished processing
       the reminder file, it puts itself in the background, and activates timed reminders when the  system  time
       reached  the  specified  time.   Note  that if you use the NOQUEUE modifier in the REM command, then this
       queuing and background activation is not performed.   NOQUEUE  is  useful  if  you  want  a  time  to  be
       associated  with a reminder (eg, in the calendar) but are not interested in a popup reminder happening at
       the specified time.

       If the trigger date is not the same as the system date, the reminder is not queued.

       For example, the following reminder, triggered every working day, will emit  a  message  telling  you  to
       leave at 5:00pm:

            REM Mon Tue Wed Thu Fri AT 17:00 MSG Time to leave!

       The following reminder will be triggered on Thursdays and Fridays, but will only be queued on Fridays:

            REM Fri ++1 AT 1:00PM MSG Lunch at 1pm Friday.

       The  tdelta  and  trepeat  have  the  same form as a repeat and delta, but are specified in minutes.  For
       example, this reminder will be triggered at 12:00pm as well as 45 minutes before:

            REM AT 12:00 +45 MSG Example

       The following will be issued starting at 10:45, every half hour until 11:45, and again at noon.

            REM AT 12:00 +75 *30 MSG Example2

       The "+75" means that the reminder is issued starting 75 minutes before noon; in other  words,  at  10:45.
       The  *30  specifies  that  the  reminder  is  subsequently  to be issued every 30 minutes.  Note that the
       reminder is always issued at the specified time, even if the tdelta is not a multiple of the trepeat.  So
       the  above  example  is  issued  at  10:45am,  11:15am,  11:45am,  and  12:00pm.   Note  that in the time
       specification, there is no distinction between the "+" and "++" forms of tdelta.

       Normally, Remind will issue timed reminders as it processes the reminder script, as well as queuing  them
       for  later.   If  you  do  not want Remind to issue the reminders when processing the script, but only to
       queue them for later, use the -a command-line option.  If you do not want  reminders  to  be  queued  for
       later, use the -q command-line option.

       Normally,  Remind forks a background process to handle queued reminders.  If you want Remind to remain in
       the foreground, use the -f command-line option.  This is useful, for example, in .xinitrc scripts,  where
       you can use the command:

            remind -fa myreminders &

       This ensures that when you exit X-Windows, the Remind process is killed.

       WARNING ABOUT TIMED REMINDERS

       Note:  If you use user-defined functions or variables (described later) in the bodies of timed reminders,
       then when the timed reminders are activated, the variables and functions have the definitions  that  were
       in effect at the end of the reminder script.  These definitions may not necessarily be those that were in
       effect at the time the reminder was queued.  In addition, the OMIT context is whatever was in  effect  at
       the  end  of the reminder script, which may not necessarily be the same as when the REM command was first
       processed.

       THE SCHED AND WARN KEYWORDS

       The SCHED keyword allows more precise control over the  triggering  of  timed  reminders,  and  the  WARN
       keyword  allows  precise  control  over  the  advance  triggering  of  all  types of reminders.  However,
       discussion must be deferred until after expressions and user-defined functions are  explained.   See  the
       subsection "PRECISE SCHEDULING" further on.

       TAG AND DURATION

       The  TAG keyword lets you "tag" certain reminders.  This facility is used by certain back-ends or systems
       built around Remind, such as TkRemind.  These  back-ends  have  specific  rules  about  tags;  see  their
       documentation for details.

       The TAG keyword is followed by a tag consisting of up to 48 characters.  You can have as many TAG clauses
       as you like in a given REM statement.  A tag can contain any character except for whitespace and a comma.

       If you supply the -y option to Remind, then any reminder that lacks a TAG will have one synthesized.  The
       synthesized  tag  consists  of the characters "__syn__" followed by the hexadecimal representation of the
       MD5 sum of the REM command line.  This lets you give a more-or-less unique identifier  to  each  distinct
       REM command.

       The  DURATION  keyword  makes sense only for timed reminders; it specifies the duration of an event.  For
       example, if you have a 90-minute meeting starting at 1:00pm, you could use any of the following:

            REM 5 March 2021 AT 13:00 DURATION 1:30 MSG Meeting
            REM 5 March 2021 AT 13:00 DURATION 90 MSG Meeting
            REM 5 March 2021 AT 1:00pm DURATION 1:30 MSG Meeting
            REM 5 March 2021 AT 1:00pm DURATION 90 MSG Meeting

       For long-duration reminders, it is convenient to use expressions to simplify writing the  DURATION.   For
       example, if you are away from 20 Feb 2023 through 23 Feb 2023 (a total of 4 days) you could write:

               REM 20 Feb AT 00:00 DURATION [4*24]:00 MSG away
               REM 20 Feb AT 00:00 DURATION [4*24*60] MSG away

       Note that duration is specified either as hours:minutes or just as minutes specified as an integer.

       If  you  specify  a duration of 00:00 or 0, then Remind behaves exactly as if no DURATION at all had been
       present.  Although durations specified as hours:minutes look superficially like a time-of-day,  they  are
       not; the hours component is not limited to the range 00-23.

SYNTACTIC SUGAR FOR REM

       The  REM  command  has  syntactic  sugar  to  let  you  express common reminders.  The following pairs of
       reminders are equivalent:

           REM First Monday April MSG Foo
           REM Mon 1 April        MSG Foo

           REM Second Monday May  MSG Bar
           REM Mon 8 May          MSG Bar

           REM Third Monday MSG Third Monday of every month
           REM Mon 15 MSG Third Monday of every month

           REM Fourth Sunday June 2025 MSG Fourth Sunday in June 2025
           REM Sun 22 June 2025 MSG Fourth Sunday in June 2025

           REM Last Monday MSG Last Monday of every month
           REM Mon 1 --7 MSG Last Monday of every month

           REM Last Monday April MSG Last Monday of every April
           REM Mon 1 May --7 MSG  Last Monday of every April

           REM Last Monday December 2025 MSG Last Monday of Dec 2025
           REM Monday 1 Jan 2026 --7 MSG Last Monday of Dec 2025

       Note that Last effectively adjusts the month and year, if necessary, to make the reminder trigger on  the
       correct date.

       The keyword IN is completely ignored, so you can write (for example):

           REM Second Monday in May MSG foo
           REM Last Monday in December 2025 MSG Bar

       An  alternate  form  of  back  makes  writing  reminders  easier.   The following groups of reminders are
       equivalent:

           REM ~~1 MSG Last day of every month
           REM Lastday MSG  Last day of every month
           REM 1 --1 MSG Last day of every month

           REM May ~~1 MSG Last day of May
           REM Lastday May MSG Last day of May
           REM 1 June --1 MSG Last day of May

           REM Dec 2025 ~~1 MSG Last day of December 2025
           REM Lastday Dec 2025 MSG Last day of December 2025
           REM 1 Jan 2026 --1 MSG Last day of December 2025

           REM Apr ~1 OMIT SAT SUN MSG Last workday of April
           REM Lastworkday April OMIT SAT SUN MSG Last workday of April
           REM 1 May -1 OMIT SAT SUN MSG Last workday of April

           REM Apr ~~7 MSG Seventh-last day of April
           REM 1 May --7 MSG Seventh-last day of April

           REM Apr ~2 OMIT SAT SUN MSG Second-last workday of April
           REM 1 May -2 OMIT SAT SUN MSG Second-last workday of April

       As we see, "Lastday" is equivalent to ~~1 and "Lastworkday" to ~1.

       Note that the First/Second/Third/Fourth/Last keywords and the ~ and ~~ form of back imply a value for the
       day    of    the   month;   as   such,   they   cannot   be   combined   with   a   day.    Additionally,
       First/Second/Third/Fourth/Last must have at least one weekday name.  The following are illegal:

           REM First Monday 3 June MSG Huh?
           REM April 3 ~~1 MSG What?
           REM Second June MSG Where's the weekday???

THE SUBSTITUTION FILTER

       Before being processed, the body of a REM command is passed through a substitution  filter.   The  filter
       scans  for  sequences  "%x"  (where  "x"  is  any  letter  and  certain  other  characters)  and performs
       substitutions as shown below.  (All dates refer to the trigger date of the reminder.)

       %a     is replaced with "on weekday, day month, year"
              For example, consider the reminder:

              REM 18 Oct 1990 +4 MSG Meeting with Bob %a.

              On 16 October 1990, it would print "Meeting with Bob on Thursday, 18 October, 1990."

              On 17 October 1990, it would print "Meeting with Bob tomorrow."

              On 18 October 1990, it would print "Meeting with Bob today."

       %b     is replaced with "in diff day's time" where diff is the actual number of days between the  current
              date and the trigger date.  (OMITs have no effect.)
              For example, consider:

              REM 18 Oct 1990 +4 MSG Meeting with Bob %b.

              On 16 October 1990, it would print "Meeting with Bob in 2 days' time."

              On 17 October 1990, it would print "Meeting with Bob tomorrow."

              On 18 October 1990, it would print "Meeting with Bob today."

       %c     is replaced with "on weekday"
              Example: REM 18 Oct 1990 +4 MSG Meeting with Bob %c.

              On 16 October 1990, it would print "Meeting with Bob on Thursday."

              On 17 October 1990, it would print "Meeting with Bob tomorrow."

              On 18 October 1990, it would print "Meeting with Bob today."

       %d     is replaced with "day", the day of the month.

       %e     is replaced with "on dd-mm-yyyy"

       %f     is replaced with "on mm-dd-yyyy"

       %g     is replaced with "on weekday, day month"

       %h     is replaced with "on dd-mm"

       %i     is replaced with "on mm-dd"

       %j     is  replaced  with  "on weekday, month day-th, year"  This form appends the characters "st", "nd",
              "rd" or "th" to the day of the month, as appropriate.

       %k     is replaced with "on weekday, month day-th"

       %l     is replaced with "on yyyy-mm-dd"

       %m     is replaced with "month", the name of the month.

       %n     is replaced with the number (1 to 12) of the month.

       %o     is replaced with " (today)" if and only if the current system date is the same as the  date  being
              used  by  Remind as the current date.  Recall that you can specify a date for Remind to use on the
              command line.  This substitution is not generally useful in a REM command,  but  is  useful  in  a
              BANNER command.  (See "The BANNER Command.")

       %p     is  replaced with "s" if the diff between the current date and the trigger date is not 1.  You can
              use this to construct reminders like:
              REM 1 Jan +4 MSG %x day%p to go before New Year!

       %q     is replaced with "'s" if the diff between the trigger date and the current date is 1.   Otherwise,
              it is replaced with "s'"  This can be used as follows:
              REM 1 Jan +4 MSG New Year in %x day%q time!

       %r     is  replaced  with  the day of the month (01 to 31) padded with a leading zero if needed to pad to
              two digits.

       %s     is replaced with "st", "nd", "rd" or "th" depending on the day of the month.

       %t     is replaced with the number of the month (01 to 12) padded to two digits with a leading zero.

       %u     is replaced with "on weekday, day-th month, year"  This is similar to %a except that  "st",  "nd",
              "rd" or "th" is added to the day as appropriate.

       %v     is replaced with "on weekday, day-th month"

       %w     is replaced with "weekday", the name of the day of the week.

       %x     is  replaced  with the diff between the current date and the trigger date.  The diff is defined as
              the actual number of  days  between  these  two  dates;  OMITs  are  not  counted.   (Strict  date
              subtraction is performed.)

       %y     is replaced with "year", the year of the trigger date.

       %z     is replaced with "yy", the last two digits of the year.

       %_     (percent-underscore)  is  replaced  with  a  newline.   You  can  use  this  to achieve multi-line
              reminders.

       %1     is replaced with "now", "m minutes from now", "m minutes ago", "h hours from now", "h hours  ago",
              "h  hours  and  m  minutes  from  now"  or "h hours and m minutes ago", as appropriate for a timed
              reminder.  Note that unless you specify the -a option, timed  reminders  will  be  triggered  like
              normal  reminders,  and  thus  a timed reminder that occurred earlier in the day may be triggered.
              This causes the need for the "...ago" forms.

       %2     is replaced with "at hh:mmam" or "..pm" depending on the AT time of the reminder.

       %3     is replaced with "at hh:mm" in 24-hour format.

       %4     is replaced with "mm" where mm is the number of minutes between "now" and the  time  specified  by
              AT.  If the AT time is earlier than the current time, then the result is negative.

       %5     is replaced with "ma" where ma is the absolute value of the number produced by %4.

       %6     is  replaced  with  "ago" or "from now", depending on the relationship between the AT time and the
              current time.

       %7     is replaced with the number of hours between the AT time and the current time.  It is always  non-
              negative.

       %8     is  replaced  with the number of minutes between the AT time and the current time, after the hours
              (%7) have been subtracted out.  This is a number ranging from 0 to 59.

       %9     is replaced with "s" if the value produced by %8 is not 1.

       %0     is replaced with "s" if the value produced by %7 is not 1.

       %!     is replaced with "is" if the current time is before the AT time, or "was" if it is after.

       %@     is similar to %2 but displays the current time.

       %#     is similar to %3 but displays the current time.

       %"     (percent-doublequote - ") is removed.  This sequence is not used by the substitution  filter,  but
              is  used  to tell Remind which text to include in a calendar entry when the -c, -s or -p option is
              chosen.  See "CALENDAR MODE"

       Notes:

       o      Remind normally prints a blank line after each reminder; if the last character of the body is "%",
              the  blank  line  will not be printed.  You can globally suppress the extra blank lines by setting
              $AddBlankLines to 0.

       o      Substitutions a, b, c, e, f, g, h, i, j, k, l, u and v  all  are  replaced  with  "today"  if  the
              current  date  equals  the  trigger  date,  or "tomorrow" if the trigger date is one day after the
              current date.  Thus, they are not the same as substitutions built up from the simpler %w, %y, etc.
              sequences.

       o      The a, c, e, f, g, h, i, j, k, l, u, v, 2, and 3 substitutions may be preceded by an asterisk (for
              example, %*c) which causes the word "at" or "on" that would normally be included in the output  to
              be omitted.

       o      Any  of  the  substitutions  dealing with time (0 through 9 and '!')  produce undefined results if
              used in a reminder that does not have an AT keyword.  Also, if a reminder has a delta and  may  be
              triggered  on several days, the time substitutions ignore the date.  Thus, the %1 substitution may
              report that a meeting is in 15 minutes, for example, even though it may only be in  2  days  time,
              because a delta has triggered the reminder.  It is recommended that you use the time substitutions
              only in timed reminders with no delta that are designed to be queued for timed activation.

       o      Capital letters can be used in the substitution sequence, in which case the first character of the
              substituted string is capitalized (if it is normally a lower-case letter.)

       o      All  other  characters  following  a "%" sign are simply copied.  In particular, to get a "%" sign
              out, use "%%" in the body.  To start the body of a reminder with a space, use "% ",  since  Remind
              normally scans for the first non-space character after a MSG, CAL or RUN token.

THE OMIT COMMAND

       In addition to being a keyword in the REM command, OMIT is a command in its own right.  Its syntax is:

              OMIT weekday [weekday...]

              or:

              OMIT [day] month [year]

              or:

              OMIT [day1] month1 [year1] THROUGH [day2] month2 [year2]

       The OMIT command is used to "globally" omit certain days (usually holidays).  These globally-omitted days
       are skipped by the "-" and "+" forms of back and delta, but  not  by  the  "--"  and  "++"  forms.   Some
       examples:

           OMIT Saturday Sunday
           OMIT 1 Jan
           OMIT 7 Sep 1992
           OMIT 15 Jan THROUGH 14 Feb
           OMIT May     # Equivalent to OMIT May 1 THROUGH May 31
           OMIT 25 Dec THROUGH 4 Jan
           OMIT 2023-05-03 THROUGH 2023-05-12
           OMIT Jun THROUGH July  # Equivalent to OMIT Jun 1 THROUGH July 31

       The  first  example omits every Saturday and Sunday.  This is useful for reminders that shouldn't trigger
       on weekends.

       The second example specifies a holiday that occurs on the same date each year - New Year's Day.

       The third example specifies a holiday that changes each year - Labour Day.  For these types of  holidays,
       you must create an OMIT command for each year.  (Later, in the description of expressions and some of the
       more advanced features of Remind, you will see how to automate this for some cases.)

       As with the REM command, you can use shorthand specifiers for dates; the following are equivalent:

            OMIT 7 Sep 1992
            OMIT 1992-09-07

       For convenience, you can use a delta and MSG or RUN keyword in the OMIT command.  The following sequences
       are equivalent:

            OMIT 1 Jan
            REM 1 Jan +4 MSG New year's day is %b!

            and

            OMIT 1 Jan +4 MSG New year's day is %b!

       The THROUGH keyword lets you conveniently OMIT a range of days.  For example, the following sequences are
       equivalent:

            OMIT 3 Jan 2011
            OMIT 4 Jan 2011
            OMIT 5 Jan 2011

            and

            OMIT 3 Jan 2011 THROUGH 5 Jan 2011

       Note that Remind has a compiled-in limit to the number of full OMITs.  If you omit a range  of  N  fully-
       specified (ie, year included) days, then N full OMITs are used up.  Trying to omit a very large range may
       result in the error "Too many full OMITs"

       You can make a THROUGH OMIT do double-duty as a REM command as long as both dates are fully specified

            OMIT 6 Sep 2010 THROUGH 10 Sep 2010 MSG Vacation

       If you use a THROUGH clause, then either the year must be supplied before and after the  THROUGH,  or  it
       must be missing before and after the THROUGH.  The following are legal:

           OMIT 25 Dec THROUGH 6 Jan
           OMIT 25 Dec 2024 THROUGH 6 Jan 2025

       But the following are not:

           OMIT 25 Dec THROUGH 6 Jan 2025
           OMIT 25 Dec 2024 THROUGH 6 Jan

       You can debug your global OMITs with the following command:

            OMIT DUMP

       The OMIT DUMP command prints the current global omits to standard output.

       THE BEFORE, AFTER AND SKIP KEYWORDS

       Normally,  days that are omitted, whether by a global OMIT command or the local OMIT or OMITFUNC keywords
       in a REM statement, only affect the counting of the -back or the +delta.  For example, suppose you have a
       meeting every Wednesday.  Suppose, too, that you have indicated 11 Nov as a holiday:

            OMIT 11 Nov +4 MSG Remembrance Day
            REM Wed +1 MSG Code meeting %b.

       The  above  sequence  will  issue  a reminder about a meeting for 11 November 1992, which is a Wednesday.
       This is probably incorrect.  There are three options:

       BEFORE This keyword moves the reminder to before any omitted days.  Thus, in the above  example,  use  of
              BEFORE would cause the meeting reminder to be triggered on Tuesday, 10 November 1992.

       AFTER  This  keyword  moves  the  reminder  to after any omitted days.  In the above example, the meeting
              reminder would be triggered on Thursday, 12 November 1992.

       SKIP   This keyword causes the reminder to be skipped completely on any omitted days.  Thus, in the above
              example,  the reminder would not be triggered on 11 November 1992.  However, it would be triggered
              as usual on the following Wednesday, 18 November 1992.

       The BEFORE and AFTER keywords move the trigger date of a reminder to before or after a block  of  omitted
       days,  respectively.   Suppose  you normally run a backup on the first day of the month.  However, if the
       first day of the month is a weekend or holiday, you run the backup on the first working day following the
       weekend or holiday.  You could use:

            REM 1 OMIT Sat Sun AFTER RUN do_backup

       Let's  examine  how the trigger date is computed.  The 1 specifies the first day of the month.  The local
       OMIT keyword causes the AFTER keyword to move the reminder forward past  weekends.   Finally,  the  AFTER
       keyword will keep moving the reminder forward until it has passed any holidays specified with global OMIT
       commands.

THE DO AND INCLUDE COMMANDS

       Remind allows you to include other files in your reminder script, similar to the C preprocessor  #include
       directive.   For  example,  your  system  administrator  may  maintain  a file of holidays or system-wide
       reminders.  You can include these in your reminder script as follows:

            INCLUDE /usr/share/remind/holidays
            INCLUDE /usr/share/remind/reminders

       (The actual pathnames vary from system to system - ask your system administrator.)

       INCLUDE files can be nested up to a depth of 8.

       If you specify a filename of "-" in the INCLUDE command, Remind will begin reading from standard input.

       If you specify a directory as the argument to INCLUDE,  then  Remind  will  process  all  files  in  that
       directory  that match the shell pattern "*.rem".  The files are processed in sorted order; the sort order
       matches that used by the shell when it expands "*.rem".

       Note that the file specified by an INCLUDE  command  is  interpreted  relative  to  the  current  working
       directory  of the Remind process.  If you want to include a file relative to the directory containing the
       currently-processing   file,   use   DO   instead.    For   example,   if    the    current    file    is
       /home/user/.reminders/foo.rem and Remind's working directory is /home/user, then:

           # Read /home/user/.reminders/bar.rem
           DO bar.rem

           # Read /usr/share/bar.rem - absolute path
           DO /usr/share/bar.rem

           # Read /home/user/bar.rem
           INCLUDE bar.rem

           # Read /usr/share/bar.rem - absolute path
           INCLUDE /usr/share/bar.rem

       Arguably,  the  INCLUDE  command should have worked the way DO does right from the start, but changing it
       would have broken backward-compatibility, hence the introduction of DO.

       Note that if the currently-processing reminders file was specified as a symbolic link to a file  that  is
       not  in  the  same directory as the symbolic link itself, DO will fail.  Remind does not resolve the real
       path of symbolic links, so you should avoid using symbolic links to files.

THE RUN COMMAND

       If you include other files in your reminder script, you may not always entirely trust the contents of the
       other files.  For example, they may contain RUN-type reminders that could be used to access your files or
       perform undesired actions.  The RUN command can restrict this:  If you include the  command  RUN  OFF  in
       your  top-level  reminder script, any reminder or expression that would normally execute a system command
       is disabled.  RUN ON will re-enable the execution of system commands.  Note that the RUN ON  command  can
       only  be  used  in  your top-level reminder script; it will not work in any files accessed by the INCLUDE
       command.  This is to protect you from someone placing a RUN ON command in an included file.  However, the
       RUN OFF command can be used at top level or in an included file.

       If  you  run  Remind with the -r command-line option, RUN-type reminders and the shell() function will be
       disabled, regardless of any RUN commands in the reminder script.  However, any command supplied with  the
       -k option will still be executed.

       In  addition,  Remind  contains a few other security features.  It will not read a file that is group- or
       world-writable.  It will not run set-uid.  If it reads a file you don't own, it will disable RUN and  the
       shell() function.  And if it is run as root, it will only read files owned by root.

       Note  that  if Remind reads standard input, it does not attempt to check the ownership of standard input,
       even if it is coming from a file, and hence does not disable RUN and shell() in this situation.

THE EXPR COMMAND

       Remind lets you completely disable expression evaluation.  This could be useful if you are running Remind
       on  a  somewhat-untrustworthy  file  that  is not expected to contain expressions.  To disable expression
       evaluation, use:

               EXPR OFF

       If Remind encounters an expression while EXPR OFF is in effect, it returns an error

       To re-enable expression evaluation, use:

               EXPR ON

       As with RUN ON, EXPR ON can be used only in the top-level script, not in an included file.

THE INCLUDECMD COMMAND

       Remind allows you to execute a shell command and evaluate the output of that command as  if  it  were  an
       included  file.   For  example, you could have scripts that extract reminders out of a database and print
       them on stdout as REM commands.  Here is an example:

            INCLUDECMD extract_reminders_for dfs

       We assume that the command "extract_reminders_for" extracts reminders out of a central database  for  the
       named  user.   Another use-case of INCLUDECMD is if you have your reminders stored in a file in some non-
       Remind format; you can write a command that  transforms  them  to  Remind  format  and  then  Remind  can
       "include" the file with an appropriate INCLUDECMD command.

       Note that if RUN is disabled, then INCLUDECMD will fail with the error message "RUN disabled"

       INCLUDECMD  passes  the  rest of the line to popen(3), meaning that the command is executed by the shell.
       As such, shell metacharacters may need escaping or arguments quoting, depending on what you're trying  to
       do.   Remind  itself  does not perform any modification of the command line (apart from the normal [expr]
       expression-pasting mechanism).

       If the command passed to INCLUDECMD begins with an exclamation mark "!", then Remind disables RUN for the
       output  of  the  command.   If  you  are running a command whose output you don't quite trust, you should
       prefix it with "!" so that any RUN commands it emits fail.

       An INCLUDECMD command counts towards the INCLUDE nesting depth.   For  any  given  Remind  run,  a  given
       INCLUDECMD  command  is  only  executed  once and the results are cached.  For example, if you generate a
       calendar, each unique INCLUDECMD command is run just  once,  not  once  for  each  day  of  the  produced
       calendar.   "Uniqueness"  is determined by looking at the command that will be passed to the shell, so if
       (for example) your INCLUDECMD uses expression-pasting that results in differences depending on the  value
       of today(), then each unique version of the command will be executed once.

THE BANNER COMMAND

       When Remind first issues a reminder, it prints a message like this:

            Reminders for Friday, 30th October, 1992 (today):

       (The  banner  is  not  printed  if  any of the calendar-producing options is used, or if the -k option is
       used.)

       The BANNER command lets you change the format.  It should appear before any REM commands.  The format is:

              BANNER format

       The format is similar to the body of a REM command.  It is passed through the substitution  filter,  with
       an implicit trigger of the current system date.  Thus, the default banner is equivalent to:

            BANNER Reminders for %w, %d%s %m, %y%o:

       You can disable the banner completely with BANNER %.  Or you can create a custom banner:

            BANNER Hi - here are your reminders for %y-%t-%r:

CONTROLLING THE OMIT CONTEXT

       Sometimes,  it is necessary to temporarily change the global OMITs that are in force for a few reminders.
       Three commands allow you to do this:

       PUSH-OMIT-CONTEXT
              This command saves the current global OMITs on an internal stack.

       CLEAR-OMIT-CONTEXT
              This command clears all of the global OMITs, starting you off with a "clean slate."

       POP-OMIT-CONTEXT
              This command restores the global OMITs that were saved by the most recent PUSH-OMIT-CONTEXT.

       For example, suppose you have a block of reminders that require a clear OMIT context, and that they  also
       introduce  unwanted  global OMITs that could interfere with later reminders.  You could use the following
       fragment:

            PUSH-OMIT-CONTEXT   # Save the current context
            CLEAR-OMIT-CONTEXT  # Clean the slate
            # Block of reminders goes here
            POP-OMIT-CONTEXT    # Restore the saved omit context

EXPRESSIONS

       In certain contexts, to be described later,  Remind  will  accept  expressions  for  evaluation.   Remind
       expressions resemble C expressions, but operate on different types of objects.

       DATA TYPES

       Remind expressions operate on five types of objects:

       INT    The  INT  data type consists of the integers representable in one machine word.  The INT data type
              corresponds to the C "int" type.

       STRING The STRING data type consists of strings  of  characters.   It  is  somewhat  comparable  to  a  C
              character array, but more closely resembles the string type in BASIC.

       TIME   The TIME data type is used for two different purposes:  To represent a time of day with one-minute
              precision or to represent a duration with one-minute precision.  The context of where  a  TIME  is
              used determines whether it is interpreted as a time of day or a duration.

              In  contexts where a TIME represents a time of day, it may range from 00:00 to 23:59 and is stored
              internally as an integer from 0 to 1439 representing the number of minutes since midnight.

              In contexts where a TIME represents a duration, there is no upper  limit  on  the  hour  component
              (beyond  that  imposed  by  the restriction that a duration expressed in minutes must fit into the
              signed integer type of your CPU architecture.)  Internally, a duration is  stored  as  an  integer
              number of minutes.

       DATE   The  DATE  data  type consists of dates (later than 1 January 1990.)  Internally, DATE objects are
              stored as the number of days since 1 January 1990.

       DATETIME
              The DATETIME data type consists of a date and time together.   Internally,  DATETIME  objects  are
              stored  as  the  number  of  minutes  since midnight, 1 January 1990.  You can think of a DATETIME
              object as being the combination of DATE and TIME parts.

       CONSTANTS

       The following examples illustrate constants in Remind expressions:

       INT constants
              12, 36, -10, 0, 1209

       STRING constants
              "Hello there", "This is a test", "\nHello\tThere", ""

              Note that the empty string is represented by "".  Remind supports the escape sequences "\a", "\b",
              "\f",  "\n",  "\r",  "\t"  and  "\v"  which have the same meanings as their counterparts in C.  To
              include a quote in a string, use "\"".  Any other character preceded by a  backslash  is  inserted
              into  the  string as-is, but the backslash itself is removed.  To include a backslash in a string,
              use "\\".

       TIME constants
              12:33, 0:01, 14:15, 16:42, 12.16, 13.00, 1.11, 4:30PM, 12:20am

              Note that TIME constants may be written in 24-hour format or in common "AM/PM" format.  If you use
              "AM/PM"  format,  then  the  hour can range from 1 to 12.  Either a period or colon can be used to
              separate the minutes from the hours.  However, Remind will consistently output  times  in  24-hour
              format  using only one separator character.  (The output separator character is chosen at compile-
              time.)

              If the TIME is used where Remind expects a time-of-day (for example, in an AT clause), then it can
              be written in 24-hour format (ranging from 00:00 to 23:59) or 12-hour format (ranging from 12:00am
              to 11:59pm).  If the TIME is used where Remind expects a duration, it must not have an  am  or  pm
              suffix  and  the  hour  can be as large as you want, so long as the total number of minutes in the
              duration fits in a signed integer variable.

       DATE constants
              DATE constants are expressed as 'yyyy/mm/dd' or  'yyyy-mm-dd',  and  the  single  quotes  must  be
              supplied.  This distinguishes date constants from division or subtraction of integers.  Examples:

              '1993/02/22', '1992-12-25', '1999/01/01'

              Note that DATE values are printed without the quotes.  Although either '-' or '/' is accepted as a
              date separator on input, when dates are printed, only one will be used.  The choice of whether  to
              use  '-'  or '/' is made at compile-time.  Note also that versions of Remind prior to 03.00.01 did
              not support date constants.  In those versions, you must create dates using the  date()  function.
              Also, versions prior to 03.00.02 did not support the '-' date separator.

       DATETIME constants
              DATETIME  constants  are  expressed  similarly  to DATE constants with the addition of an "@HH:MM"
              part, optionally followed by "am" or "pm".  For example:

              '2008-04-05@23:11', '1999/02/03@14:06', '2001-04-07@08:30', '2020-01-01@3:20pm'

              DATETIME values are printed without the quotes.  Notes about date and  time  separator  characters
              for DATE and TIME constants apply also to DATETIME constants.

       ZERO VALUES

       The non-string types all have an associated zero value, which is treated as "false" by the IF command and
       the logical operators.  The zero values are:

              INT - 0

              DATE - '1990-01-01'

              TIME - 00:00

              DATETIME - '1990-01-01@00:00'

       Additionally, for the purpose of the IF command (but not the logical operators) the empty  string  ""  is
       considered a false value.

       OPERATORS

       Remind has the following operators.  Operators on the same line have equal precedence, while operators on
       lower lines have lower precedence than those on higher lines.  The operators approximately correspond  to
       C operators.

            !  -            (unary logical negation and arithmetic negation)
            *  /  %         (multiplication, division, modulus)
            +  -            (addition/concatenation, subtraction)
            <  <=  >  >=    (comparisons)
            ==  !=          (equality and inequality tests)
            &&              (logical AND)
            ||              (logical OR)

       DESCRIPTION OF OPERATORS

       !      Logical  negation.   Can  be  applied  to  an INT type.  If the operand is non-zero, returns zero.
              Otherwise, returns 1.

       -      Unary minus.  Can be applied to an INT.  Returns the negative of the operand.

       *      Multiplication.  Returns the product of two INTs.  Alternatively, if one argument is a STRING  and
              the other an INT, returns a STRING consisting of the INT number of repeats of the original STRING.
              In this case, the INT argument cannot be negative.

       /      Integer division.  Returns the quotient of two INTs, discarding the remainder.

       %      Modulus.  Returns the remainder upon dividing one INT by another.

       +      Has several uses.  These are:

              INT + INT - returns the sum of two INTs.

              INT + TIME or TIME + INT - returns a TIME obtained by adding INT minutes  to  the  original  TIME.
              The result will always range from 00:00 through 23:59.

              TIME  + TIME treats the second TIME parameter as a duration, converting it to an integer number of
              minutes past midnight, and then performs addition as with TIME + INT.

              INT + DATE or DATE + INT - returns a DATE obtained by adding INT days to the original DATE.

              INT + DATETIME or DATETIME + INT - returns a DATETIME  obtained  by  adding  INT  minutes  to  the
              original DATETIME.

              DATETIME  +  TIME  or TIME + DATETIME treats the TIME parameter as a duration, converting it to an
              integer number of minutes past midnight, and then performs addition as with DATETIME + INT.

              STRING + STRING - returns a STRING that is the concatenation of the two original STRINGs.

              STRING + anything or anything + STRING - converts the non-STRING argument to a  STRING,  and  then
              performs concatenation.  See the coerce() function.

       -      Has several uses.  These are:

              INT - INT - returns the difference of two INTs.

              DATE - DATE - returns (as an INT) the difference in days between two DATEs.

              TIME - TIME - returns (as an INT) the difference in minutes between two TIMEs.

              DATETIME - DATETIME - returns (as an INT) the difference in minutes between two DATETIMEs.

              DATE - INT - returns a DATE that is INT days earlier than the original DATE.

              TIME - INT - returns a TIME that is INT minutes earlier than the original TIME.

              DATETIME - INT - returns a DATETIME that is INT minutes earlier than the original DATETIME.

              DATETIME - TIME - coerces the TIME to an INT and then performs subtraction as above.

       <, <=, >, and >=
              These are the comparison operators.  They can take operands of any type, but both operands must be
              of the same type.  The comparison operators return 1 if the comparison is true,  or  0  if  it  is
              false.   Note  that string comparison is done following the lexical ordering of characters on your
              system, and that upper and lower case are distinct for these operators.

       ==, != == tests for equality, returning 1 if its operands are equal, and 0 if they are not.  != tests for
              inequality.

              If  the  operands  are  not  of  the  same  type,  ==  returns  0 and != returns 1.  Again, string
              comparisons are case-sensitive.

       &&     This is the logical AND operator.  Neither of its operands can be STRING type.  Returns the second
              operand if both operands are non-zero.  Otherwise, returns whichever operand is zero.

       ||     This  is  the  logical  OR  operator.  Neither of its operands can be STRING type.  It returns the
              first operand that is non-zero; if both operands are zero, then returns the second operand.

       NOTES

       If the result of an addition, subtraction or multiplication operation would not fit in a  C  "int"  type,
       Remind  issues  a  "Number  too high" error.  Unlike C, integer operations will not simply give the wrong
       answer in case of overflow.

       Operators of equal precedence are always evaluated from left to right, except where  parentheses  dictate
       otherwise.   This  is  important,  because the enhanced "+" operator is not necessarily associative.  For
       example:

            1 + 2 + "string" + 3 + 4  yields "3string34"
            1 + (2 + "string") + (3 + 4)  yields "12string7"
            12:59 + 1 + "test"  yields "13:00test"
            12:59 + (1 + "test")  yields "12:591test"

       The logical operators are so-called short-circuit operators, as they are in C.  This means  that  if  the
       first  operand  of || is true, then the second operand is not evaluated.  Similarly, if the first operand
       of && is false, then the second operand is not evaluated.

       VARIABLES

       Remind allows you to assign values to variables.  The SET command is used as follows:

       SET var expr

       Var is the name of a variable.  It must start with a letter or underscore, and consist only  of  letters,
       digits and underscores.  Only the first 64 characters of a variable name are significant.  Variable names
       are not case sensitive; thus, "Afoo" and "afOo" are the same variable.  Examples:

            SET a 10 + (9*8)
            SET b "This is a test"
            SET mydir getenv("HOME")
            SET time 12:15
            SET date today()

       Note that variables themselves have no type.  They take on the type of whatever you store in them.

       Variables set with SET or on the command-line with -ivar=expr have global scope.

       To delete a variable, use the UNSET command:

       UNSET var [var...]

       For example, to delete all the variables declared above, use:

            UNSET a b mydir time date

       SYSTEM VARIABLES

       In addition to the regular user variables, Remind has several "system variables" that are used  to  query
       or  control the operating state of Remind.  System variables are available starting from version 03.00.07
       of Remind.

       All system variables begin with a dollar sign '$'.  They can be used in SET commands and expressions just
       as  regular  variables  can.   All system variables always hold values of a specified type.  In addition,
       some system variables cannot be modified, and you cannot create new system variables.   System  variables
       can be initialized on the command line with the -i option, but you may need to quote them to avoid having
       the shell interpret the dollar sign.  System variable names are not case-sensitive.

       The following system variables are defined.  Those marked "read-only" cannot  be  changed  with  the  SET
       command.  All system variables hold values of type INT, unless otherwise specified.

       $AddBlankLines
              If  set  to  1  (the  default), then Remind normally prints a blank line after the banner and each
              reminder.  (This can be suppressed by ending the reminder or banner with a single  percent  sign.)
              If  $AddBlankLines is set to 0, then Remind does not print the blank line.  In this case, ending a
              reminder with % has no effect.  If you do want a blank line after a reminder, end it  with  %_  to
              insert a newline.

       $CalcUTC
              If  1  (the  default),  then  Remind  uses  C library functions to calculate the number of minutes
              between local and Universal Time Coordinated.  This affects astronomical  calculations  (sunrise()
              for  example.)   If 0, then you must supply the number of minutes between local and Universal Time
              Coordinated in the $MinsFromUTC system variable.

       $CalMode (read-only)
              If non-zero, then the -c option was supplied on the command line.

       $Daemon (read-only)
              If "daemon mode" -z was invoked, contains the number of minutes between wakeups.  If  not  running
              in daemon mode, contains 0.  In server mode (either -z0 or -zj), contains -1.

       $DateSep
              This  variable can be set only to "/" or "-".  It holds the character used to separate portions of
              a date when Remind prints a DATE or DATETIME value.

       $DefaultColor
              This variable can be set to a string that has the form of  three  space-separated  numbers.   Each
              number  must  be  an integer from 0 to 255, or all three numbers must be -1.  The default value of
              $DefaultColor is "-1 -1 -1", which suppresses default coloring of MSG-type reminders.  If you  set
              $DefaultColor  to  any  other  value,  then  all MSG-, MSF- and CAL-type reminders are effectively
              converted into SPECIAL COLOR reminders whose color value is specified by $DefaultColor.

              Unlike other system variables, the value  of  $DefaultColor  is  not  preserved  between  calendar
              iterations; rather, it is reset to "-1 -1 -1" at the start of each iteration.

       $DefaultPrio
              The  default  priority  assigned  to  reminders  without  a  PRIORITY clause.  You can set this as
              required to adjust the priorities of blocks of reminders without having  to  type  priorities  for
              individual reminders.  At startup, $DefaultPrio is set to 5000; it can range from 0 to 9999.

       $DefaultTDelta
              The default time delta used if no +N is given in an AT clause.  This is normally 0, but can be set
              with the -tt option or explicitly set in your script.  If $DefaultDelta is non-zero, you  can  use
              an explicit delta of +0 in an AT clause to countermand the default delta.

       $DeltaOverride (read-only)
              If non-zero, corresponds to the n argument given to a -tn command-line option.

       $DontFork (read-only)
              If non-zero, then the -c option was supplied on the command line.

       $DontTrigAts (read-only)
              The number of times that the -a option was supplied on the command line.

       $DontQueue (read-only)
              If non-zero, then the -q option was supplied on the command line.

       $EndSent (STRING type)
              Contains a list of characters that end a sentence.  The MSF keyword inserts two spaces after these
              characters.  Initially, $EndSent is set to ".!?" (period, exclamation mark, and question mark.)

       $EndSentIg (STRING type)
              Contains a list of characters that should be ignored when MSF decides whether or not to place  two
              spaces after a sentence.  Initially, is set to "'>)]}"+CHAR(34) (single-quote, greater-than, right
              parenthesis, right bracket, right brace, and double-quote.)

              For example, the default values work as follows:

                   MSF He said, "Huh! (Two spaces will follow this.)"  Yup.

              because the final parenthesis and quote are ignored (for the purposes of spacing) when they follow
              a period.

       $ExpressionTimeLimit
              If  set  to  a  non-zero value n, than any expression that takes longer than n seconds to evaluate
              will be aborted and an error returned.  This is to  prevent  maliciously-crafted  expressions  for
              creating  a denial-of-service.  In an included file, $ExpressionTimeLimit can only be lowered from
              its current value.  In the top-level file, it can be set to any value, including zero  to  disable
              the time limit.

       $FirstIndent
              The number of spaces by which to indent the first line of a MSF-type reminder.  The default is 0.

       $FoldYear
              The  standard  Unix  library functions may have difficulty dealing with dates later than 2037.  If
              this variable is set to 1, then the UTC calculations "fold back"  years  later  than  2037  before
              using the Unix library functions.  For example, to find out whether or not daylight saving time is
              in effect in June, 2077, the year is "folded back" to 2010, because both years begin on a  Monday,
              and  both are non-leapyears.  The rules for daylight saving time are thus presumed to be identical
              for both years, and the Unix library functions can handle 2010.  By default, this variable  is  0.
              Set it to 1 if the sun or UTC functions misbehave for years greater than 2037.

       $FormWidth
              The  maximum  width  of  each  line of text for formatting MSF-type reminders.  The default is the
              width of the terminal in columns, minus 8, but clamped at a minimum of 20 and a  maximum  of  500.
              If  standard  output  is not a terminal, then the default is 72.If an MSF-type reminder contains a
              word too long to fit in this width, it will not be truncated - the width limit will be ignored.

       $HushMode (read-only)
              If non-zero, then the -h option was supplied on the command line.

       $IgnoreOnce (read-only)
              If non-zero, then the -o option was supplied on the command line, or implicitly enabled  for  some
              other reason.  In this case, ONCE directives will be ignored.

       $InfDelta (read-only)
              If non-zero, then the -t option was supplied on the command line, with no n argument.

       $IntMax (read-only)
              The  largest  representable  INT.   On a machine with 32-bit signed integers using twos-complement
              representation, this will be 2147483647.

       $IntMin (read-only)
              The smallest representable INT.  On a machine with 32-bit signed  integers  using  twos-complement
              representation, this will be -2147483648.

       $Latitude (STRING type)
              The  latitude  of  your  location, expressed as a string that is a floating-point number.  Because
              Remind does not have a native floating-point type, we need to express it as a  string.   $Latitude
              can  range  from "-90.0" to "90.0", with positive numbers representing points north of the equator
              and negative numbers representing south.  Note that regardless of your locale, $Latitude is always
              interpreted in the "C" locale and as such, the decimal point must be a period (".").

       $Longitude (STRING type)
              The  longitude  of  your location, expressed as a string that is a floating-point number.  Because
              Remind does not have a native floating-point type, we need to express it as a string.   $Longitude
              can  range  from  "-180.0"  to  "180.0",  with  positive  numbers  representing points east of the
              Greenwich Meridian and negative numbers representing west.  Note that regardless of  your  locale,
              $Longitude is always interpreted in the "C" locale and as such, the decimal point must be a period
              (".").

              For example, the coordinates of the Statue of Liberty in New York City are approximately set by:

                  SET $Latitude   "40.68933"
                  SET $Longitude "-74.04454"

       $LatDeg, $LatMin, $LatSec (DEPRECATED)
              These specify the latitude of your location.  $LatDeg can range from -90 to  90,  and  the  others
              from  -59  to  59.   Northern  latitudes  are  positive; southern ones are negative.  For southern
              latitudes, all three components should be negative.  These three  variables  are  deprecated;  you
              should use $Latitude instead.

       $Location (STRING type)
              This  is  a  string  specifying the name of your location.  It is usually the name of your town or
              city.  It can be set to whatever you like, but  good  style  indicates  that  it  should  be  kept
              consistent with the latitude and longitude system variables.

       $LongDeg, $LongMin, $LongSec (DEPRECATED)
              These  specify  the  longitude  of  your  location.  $LongDeg can range from -180 to 180.  Western
              longitudes are positive; eastern ones are negative.  Note that all three  components  should  have
              the  same sign: All positive for western longitudes and all negative for eastern longitudes.  Note
              that for historical reasons, the sign for longitude is different from the  usual  convention!   If
              you  find the longitude of your location from a search engine, you will most likely need to invert
              the sign to have it work correctly with Remind. These three variables are deprecated;  you  should
              use  $Longitude  instead.   Note also that $Longitude uses the standard convention of negative for
              western longitudes and positive for eastern ones.

              The latitude and longitude information is required  for  the  functions  sunrise()  and  sunset().
              Default values can be compiled into Remind, or you can SET the correct values at the start of your
              reminder scripts.

              Note that setting any of $LongDec, $LongMin and $LongSec updates $Longitude  correspondingly,  and
              setting  $Longitude  updates  $LongDeg,  $LongMin and $LongSec.  Similar rules apply to $Latitude,
              $LatDeg, $LatMin and $LatSec.

       $MaxLateMinutes
              This variable controls how Remind reacts to a computer being suspended and then woken.   Normally,
              if  a  timed  reminder  is  queued and then the computer suspended, and then the computer is woken
              after the timed reminder's trigger time, Remind will triger the timer  anyway,  despite  the  fact
              that the trigger time has already passed.

              If  you set $MaxLateMinutes to a non-zero integer between 1 and 1440, then Remind will not trigger
              a timed reminder whose trigger time is more than $MaxLateMinutes minutes in the past.

              Note that Remind uses the value of $MaxLateMinutes that is in effect when it has finished  reading
              the  reminder  file  and puts itself in the background.  Generally, you should set $MaxLateMinutes
              once near the beginning of the file and not change it after that.

       $MaxSatIter
              The maximum number of iterations for the SATISFY clause (described later.)  Must be at least 10.

       $MaxStringLen
              A limit on the longest string that Remind will allow you to create.  The default is 65535.  If you
              set $MaxStringLen to 0 or to -1, then remind will allow you to create arbitrarily-long strings, at
              least until it runs out of memory.  We do not recommend setting $MaxStringLen to 0 or  -1  because
              it is very easy to write code that DOSes Remind in that case.

       $MinsFromUTC
              The number of minutes between Universal Time Coordinated and local time.  If $CalcUTC is non-zero,
              this is calculated upon startup of Remind.  Otherwise, you must set it explicitly.  If $CalcUTC is
              zero, then $MinsFromUTC is used in the astronomical calculations.  You must adjust it for daylight
              saving time yourself.  Also, if you want to initialize  $MinsFromUTC  using  the  -i  command-line
              option, you must also set $CalcUTC to 0 with the -i option.

       $NextMode (read-only)
              If non-zero, then the -n option was supplied on the command line.

       $MaxFullOmits (read-only)
              The maximum number of full OMITs allowed (a compiled-in constant.)

       $MaxPartialOmits (read-only)
              The maximum number of partial OMITs allowed (a compiled-in constant.)

       $NumFullOmits (read-only)
              The number of full OMITs in the current OMIT context.

       $NumPartialOmits (read-only)
              The number of partial OMITs in the current OMIT context.

       $NumQueued (read-only)
              Contains the number of reminders queued so far for background timed triggering.

       $NumTrig (read-only)
              Contains  the number of reminders triggered for the current date.  One use for this variable is as
              follows:  Suppose you wish to shade in the box of a PostScript  calendar  whenever  a  holiday  is
              triggered.   You could save the value of $NumTrig in a regular variable prior to executing a block
              of holiday reminders.  If the value of $NumTrig after the holiday block is greater than the  saved
              value,  then  at  least one holiday was triggered, and you can execute the command to shade in the
              calendar box.  (See the section "Calendar Mode".)

              Note that $NumTrig is affected only by REM commands; triggers in IFTRIG commands do not affect it.

       $OnceFile (STRING type)
              If you set this variable to a non-empty string, then rather than using the  file  access  date  to
              determine whether or not to run a ONCE-type reminder, Remind will maintain a timestamp in the file
              $OnceFile.  This is more reliable than using the access date of the reminder file.

              If $OnceFile does not exist, then it will be created the first time a ONCE keyword  is  processed.
              The  file must be writable by the current user.  If you try to set $OnceFile after a ONCE reminder
              has already been processed, Remind will issue a warning and ignore the attempt to set $OnceFile.

       $ParseUntriggered
              A flag indicating whether or not Remind should fully parse REM statements that are not  triggered.
              0 means to skip parsing them and 1 (the default) means to parse them.

              For example, if we have the following REM statement:

                          REM 2020-01-01 MSG ["bad_expression" * 2]

              Then  by  default,  Remind will fully parse the line and issue a "Type mismatch" error even if the
              reminder is not triggered.  However, if $ParseUntriggered is set to 0, then Remind will not  issue
              the error except on 2020-01-01, when the reminder is triggered.

              Setting  $ParseUntriggered to 0 may in some cases slightly improve performance, at the risk of not
              catching errors until a reminder is triggered.

       $PrefixLineNo (read-only)
              If non-zero, then the -l option was supplied on the command line.

       $PSCal (read-only)
              If non-zero, then the -p option was supplied on the command line.

       $RunOff (read-only)
              If non-zero, the RUN directives are disabled.

       $SimpleCal (read-only)
              Set to a non-zero value if either of the -p or -s command-line options was supplied.

       $SortByDate (read-only)
              Set to 0 if no -g option is used, 1 if sorting by date in ascending order, or 2 if sorting by date
              in descending order.

       $SortByPrio (read-only)
              Set  to 0 if no -g option is used, 1 if sorting by priority in ascending order, or 2 if sorting by
              priority in descending order.

       $SortByTime (read-only)
              Set to 0 if no -g option is used, 1 if sorting by time in ascending order, or 2 if sorting by time
              in descending order.

       $SubsIndent
              The  number  of  spaces  by  which  all lines (except the first) of an MSF-type reminder should be
              indented.  The default is 0.

       $SuppressLRM
              Normally, when Remind is run with the -c option in a UTF-8 locale, it emits a  left-to-right  mark
              sequence  after  printing  day names or reminders.  Some terminals render this incorrectly, so you
              can use:

                  SET $SuppressLRM 1

              at the top of your reminder file to suppress the LRM sequences, or you can invoke Remind with  the
              option '-i$SuppressLRM=1'.

       $SysInclude (read-only, STRING type)
              A directory path containing standard reminder scripts.  Currently, Remind ships with some standard
              holiday files and language packs.   The  value  of  $SysInclude  is  "/usr/share/remind"  on  this
              installation.

       $T (read-only, DATE type)
              Exactly equivalent to trigdate().  (See BUILT-IN FUNCTIONS.)

       $Td (read-only)
              Equivalent to day(trigdate()).

       $Tm (read-only)
              Equivalent to monnum(trigdate()).

       $Tw (read-only)
              Equivalent to wkdaynum(trigdate()).

       $Ty (read-only)
              Equivalent to year(trigdate()).

       $Tt (read-only, TIME type)
              Equivalent to trigtime().

       $TimeSep
              This  variable can be set only to ":" or ".".  It holds the character used to separate portions of
              a time when Remind prints a TIME or DATETIME value.

       $UntimedFirst (read-only)
              Set to 1 if the -g option is used with a fourth sort character of "d"; set to 0 otherwise.

       $U (read-only, DATE type)
              Exactly equivalent to today().  (See BUILT-IN FUNCTIONS.)

       $Ud (read-only)
              Equivalent to day(today()).

       $Um (read-only)
              Equivalent to monnum(today()).

       $Uw (read-only)
              Equivalent to wkdaynum(today()).

       $Uy (read-only)
              Equivalent to year(today()).

       $UseVTColors (read-only)
              Set to 1 if the -@ or -cc options were used; 0 otherwise.

       $UseBGVTColors (read-only)
              Set to 1 if the -@,,1 option was used; 0 otherwise.

       $Use256Colors (read-only)
              Set to 1 if the -@1 option was used; 0 otherwise.

       $UseTrueColors (read-only)
              Set to 1 if the -@2 option was used; 0 otherwise.

       $TerminalBackground (read-only)
              Returns -1 if the terminal background color could not be determined, 0 if it was found to be  dark
              (or  was specified as dark with the -@,0 option) or 1 if it was found to be light (or specified as
              light with the -@,1 option.)  The terminal background is considered to be "dark" if the average of
              the  red,  green and blue components is at most 85 out of 255, and if the maximum of any component
              is at most 128 out of 255.

       Note:  If any of the calendar modes are in effect, then the values of $Daemon,  $DontFork,  $DontTrigAts,
       $DontQueue, $HushMode, $IgnoreOnce, $InfDelta, and $NextMode are not meaningful.

       BUILT-IN FUNCTIONS

       Remind  has  a  plethora of built-in functions.  The syntax for a function call is the same as in C - the
       function name, followed a comma-separated list of arguments in parentheses.  Function names are not case-
       sensitive.   If  a  function  takes  no  arguments,  it  must  be  followed by "()" in the function call.
       Otherwise, Remind will interpret it as a variable name, and probably not work correctly.

       In the descriptions below, short forms are used to  denote  acceptable  types  for  the  arguments.   The
       characters  "i",  "s",  "d",  "t"  and  "q"  denote  INT,  STRING,  DATE,  TIME  and  DATETIME arguments,
       respectively.  If an argument can be one of several types, the characters are concatenated.  For example,
       "di_arg"  denotes  an  argument that can be a DATE or an INT.  "x_arg" denotes an argument that can be of
       any type.  The type of the argument is followed by an underscore and an identifier naming the argument.

       The built-in functions are:

       abs(i_num)
              Returns the absolute value of num.

       access(s_file, si_mode)
              Tests the access permissions for the file file.  Mode can be a string, containing  a  mix  of  the
              characters  "rwx"  for  read,  write and execute permission testing.  Alternatively, mode can be a
              number as described in the UNIX access(2) system call.  The function returns 0 if the file can  be
              accessed with the specified mode, and -1 otherwise.

       adawn([dq_date])
              Returns  the  time  of "astronomical dawn" on the specified date.  If date is omitted, defaults to
              today().  If a datetime object is supplied, only the date component is used.

       adusk([dq_date])
              Returns the time of "astronomical twilight" on the specified date.  If date is  omitted,  defaults
              to today().

       ampm(tq_time [,s_am [,s_pm]])
              Returns  a  STRING  that  is  the  result of converting time (which is either a TIME or a DATETIME
              object) to "AM/PM" format.  The optional arguments am and pm are the strings to append in  the  AM
              and PM case, respectively; they default to "AM" and "PM".  The function obeys the system variables
              $DateSep, $TimeSep and $DateTimeSep when formatting its output.  For example:

                      ampm(0:22)                 returns "12:22AM"
                      ampm(17:45, "am", "pm")    returns "5:45pm"
                      ampm('2020-03-14@21:34')   returns "2020-03-14@9:34PM"

       ansicolor(i_red, i_green, i_blue [,i_bg [,i_clamp]])
              Returns a STRING that contains an ANSI escape sequence for changing the terminal text color.   The
              parameters  red,  green and blue are integers from 0 to 255 specifying the value of the respective
              color component.  As a special case, all three values can be -1, in which case the  ANSI  sequence
              "ESC[0m" is returned, which resets all text attributes to normal.

              The string returned by ansicolor depends on the color mode that Remind is running in, as specified
              by the -@ option.  If color mode is not enabled, then ansicolor always returns the  empty  string.
              Otherwise,  it  returns  the  escape sequence that best approximates the color according to the -@
              color mode.

              The optional bg argument is either 0 or 1.  If 0 (the default), then the foreground color is  set.
              If  1,  then  the  background  color is set.  Note that setting the background color only works in
              256-color or true-color mode.

              The optional clamp argument is either 0 or 1.  If 0 (the default), then colors  are  not  adjusted
              based  on  the  terminal  background  color.   If 1, then Remind attempts to adjust dark or bright
              colors so they have enough contrast to be visible in the terminal.

              The first three arguments may alternatively be specified as a string consisting  of  three  space-
              separated numbers, as in this example: "128 128 0"

              As  a  special  case,  ansicolor("")  is  equivalent  to  ansicolor(-1,-1,-1) and returns the ANSI
              sequence to reset all text attributes to normal.

              Note that  inserting  ANSI  color  sequences  in  calendar  mode  will  produce  garbled  results.
              Therefore,  we recommend defining functions such as the ones below that return the empty string in
              calendar mode:

                      IF $CalMode
                          FSET fg(r,g,b) ""
                          FSET bg(r,g,b) ""
                      ELSE
                          FSET fg(r,g,b) ansicolor(r,g,b)
                          FSET bg(r,g,b) ansicolor(r,g,b,1)
                      ENDIF
                      REM [fg(255,0,0)][bg(64,64,64)]Red on Gray[fg(-1,-1,-1)] in normal mode
                      REM SPECIAL COLOR 0 255 0 Green in normal and calendar mode

              If you use the  ansicolor  function,  don't  forget  to  reset  the  color  back  to  normal  with
              ansicolor(-1,-1,-1) or subsequent reminders will continue to be colored.

       args(s_fname)
              Returns  the  number  of  arguments  expected by the user-defined function fname, or -1 if no such
              user-defined function exists.  Note that this function examines only user-defined  functions,  not
              built-in  functions.   Its  main  use  is  to  determine  whether or not a particular user-defined
              function has been defined previously.  The args() function is available only in versions of Remind
              from 03.00.04 and up.

       asc(s_string)
              Returns  an  INT  that  is  the  ASCII  code of the first character in string.  As a special case,
              asc("") returns 0.  For UTF-8 strings, this will return the  UTF-8  byte  with  which  the  string
              begins,  which  is not likely to be very useful (and may indeed be negative on machines where char
              is a signed type.)

       baseyr()
              Returns the "base year" that was compiled into Remind  (normally  1990.)   All  dates  are  stored
              internally as the number of days since 1 January of baseyr().

       char(i_i1 [,i_i2...])
              This  function  can take any number of INT arguments.  It returns a STRING consisting of the bytes
              specified by the arguments.  It is easy to create invalid UTF-8 sequences; char does not check for
              this.   Note that none of the arguments can be 0, unless there is only one argument.  As a special
              case, char(0) returns "".

       choose(i_index, x_arg1 [,x_arg2...])
              Choose must take at least two arguments, the first of which is an INT.  If index is  n,  then  the
              nth subsequent argument is returned.  If index is less than 1, then arg1 is returned.  If index is
              greater than the number of subsequent arguments, then the last argument is returned.  Examples:

                 choose(0, "foo", 1:13, 1000) returns "foo"
                 choose(1, "foo", 1:13, 1000) returns "foo"
                 choose(2, "foo", 1:13, 1000) returns 1:13
                 choose(3, "foo", 1:13, 1000) returns 1000
                 choose(4, "foo", 1:13, 1000) returns 1000
              Note that all arguments to choose() are always evaluated.

       coerce(s_type, x_arg)
              This function converts arg to the specified type, if such conversion is possible.   Type  must  be
              one of "INT", "STRING", "DATE", "TIME" or "DATETIME" (case-insensitive).  The conversion rules are
              as follows:

              If arg is already of the type specified, it is returned unchanged.

              If type is "STRING", then arg is converted to a string consisting of its printed representation.

              If type is "DATE", then an INT arg is converted by interpreting it as the number of days  since  1
              January  baseyr().   A  STRING  arg  is converted by attempting to read it as if it were a printed
              date.  A DATETIME is converted to a date by dropping the time component.  A  TIME  arg  cannot  be
              converted to a date.

              If  type is "TIME", then an INT arg is converted by interpreting it as the number of minutes since
              midnight.  A STRING arg is converted by attempting to read it as if it were  a  printed  time.   A
              DATETIME is converted to a time by dropping the date component.  A DATE arg cannot be converted to
              a time.

              If type is "DATETIME", then an INT arg is converted by interpreting it as the  number  of  minutes
              since  midnight, 1 January baseyr().  A STRING is converted by attempting to read it as if it were
              a printed datetime.  Other types cannot be converted to a datetime.

              If type is "INT", then DATE, TIME and DATETIME  arguments  are  converted  using  the  reverse  of
              procedures described above.  A STRING arg is converted by parsing it as an integer.

       columns([s_arg])
              If  called  with  no arguments, columns() behaves as follows: If standard output is a TTY, returns
              the width of the terminal in columns.   If  standard  output  is  not  a  TTY,  attempts  to  open
              "/dev/tty" to obtain the terminal size.  If this fails, returns -1.

              If  called  with  a  single  string  argument, columns(str) returns the number of columns str will
              occupy if printed to a terminal.  ANSI color-changing sequences occupy zero columns  whereas  some
              Unicode characters occupy two columns.  columns(str) takes all of that into account.  Note that if
              Remind was compiled without Unicode support, columns(str) returns a type mismatch error.

       current()
              Returns the current date and time as a DATETIME object.  This may be the actual date and time,  or
              may be the date and time supplied on the command line.

       date(i_y, i_m, i_d)
              The  date() function returns a DATE object with the year, month and day components specified by y,
              m and d.

       datepart(dq_datetime)
              Returns a DATE object representing the date portion of datetime.

       datetime(args)
              The datetime() function can take anywhere from  two  to  five  arguments.   It  always  returns  a
              DATETIME generated from its arguments.

              If you supply two arguments, the first must be a DATE and the second a TIME.

              If  you  supply  three  arguments, the first must be a DATE and the second and third must be INTs.
              The second and third arguments are interpreted as hours and minutes and converted to a TIME.

              If you supply four arguments, the first three must be INTs, interpreted as  the  year,  month  and
              day.  The fourth argument must be a TIME.

              Finally,  if  you supply five arguments, they must all be INTs and are interpreted as year, month,
              day, hour and minute.

       dawn([dq_date])
              Returns the time of "civil dawn" on the specified date.  If date is omitted, defaults to  today().
              If a datetime object is supplied, only the date component is used.

       day(dq_date)
              This function takes a DATE or DATETIME as an argument, and returns an INT that is the day-of-month
              component of date.

       daysinmon(i_m, i_y)
              Returns the number of days in month m (1-12) of the year y.

       defined(s_var)
              Returns 1 if the variable named by var is defined, or 0 if it is not.
              Note that defined() takes a STRING argument; thus, to check if variable X is defined, use:

                        defined("X")

              and not:

                        defined(X)

              The second example will attempt to evaluate X, and will return an error if it is undefined or  not
              of type STRING.

       dosubst(s_str [,d_date [,t_time]]) or dosubst(s_str [,q_datetime])
              Returns  a  STRING  that  is  the  result of passing str through the substitution filter described
              earlier.  The parameters date and time (or datetime) establish the effective trigger date and time
              used by the substitution filter.  If date and time are omitted, they default to today() and now().

              Note  that  if  str  does  not  end  with "%", a newline character will be added to the end of the
              result.  Also, calling dosubst() with a date that is in the past (i.e., if date  <  today())  will
              produce undefined results.

              Dosubst() is only available starting from version 03.00.04 of Remind.

       dusk([dq_date])
              Returns  the  time  of  "civil  twilight"  on the specified date.  If date is omitted, defaults to
              today().

       easterdate([dqi_arg])
              If arg is an INT, then returns the date of Easter Sunday for the specified year.  If arg is a DATE
              or DATETIME, then returns the date of the next Easter Sunday on or after arg.  (The time component
              of a datetime is ignored.)  If arg is omitted, then it defaults to today().

              Note  that  easterdate  computes  the  Western  Easter.   For  the  Orthodox  Easter   date,   see
              orthodoxeaster.

       evaltrig(s_trigger [,dq_start])
              Evaluates trigger as if it were a REM or IFTRIG trigger specification and returns the trigger date
              as a DATE (or as a DATETIME if there is an AT clause.)  Returns a negative INT if no trigger could
              be computed.

              Normally, evaltrig finds a trigger date on or after today.  If you supply the start argument, then
              it scans starting from there.

              For example, the expression:

                evaltrig("Mon 1", '2008-10-07')

              returns '2008-11-03', since that is the first date on or after 7 October 2008 that satisfies  "Mon
              1".

              If  you want to see how many days it is from the first Monday in October, 2008 to the first Monday
              in November, 2008, use:

                evaltrig("Mon 1", '2008-11-01') - evaltrig("Mon 1", '2008-10-01')

              and the answer is 28.  The trigger argument to evaltrig can have all  the  usual  trigger  clauses
              (OMIT, AT, SKIP, etc.) but cannot have a SATISFY, MSG, etc. reminder-type clause.

       filedate(s_filename)
              Returns  the  modification date of filename.  If filename does not exist, or its modification date
              is before the year baseyr(), then 1 January of baseyr() is returned.

       filedatetime(s_filename)
              Returns the modification date  and  time  of  filename.   If  filename  does  not  exist,  or  its
              modification date is before the year baseyr(), then midnight, 1 January of baseyr() is returned.

       filedir()
              Returns  the  directory  that  contains the current file being processed.  It may be a relative or
              absolute pathname, but is guaranteed to be correct for use in an INCLUDE command as follows:

                 INCLUDE [filedir()]/stuff

              This includes the file "stuff" in the same directory as the current file  being  processed.   Note
              that this workaround is no longer necessary because DO stuff will achieve the same goal.

              Note  that  if  the  currently-processing  reminders  file  was specified as a symbolic link, then
              filedir() returns the directory containing the symbolic link and not the directory containing  the
              target  of  the  symbolic  link.   You  should avoid using symbolic links to files unless both the
              symbolic link and its target happen to be in the same directory.

       filename()
              Returns (as a STRING) the name of the current file being processed  by  Remind.   Inside  included
              files, returns the name of the included file.

       getenv(s_envvar)
              Similar  to  the  getenv(2) system call.  Returns a string representing the value of the specified
              environment variable.  Returns "" if the environment variable is not defined.  Note that the names
              of  environment  variables  are  generally case-sensitive; thus, getenv("HOME") is not the same as
              getenv("home").

       hebdate(i_day, s_hebmon [,idq_yrstart [,i_jahr [,i_aflag]]])
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hebday(dq_date)
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hebmon(dq_date)
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hebyear(dq_date)
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hour(tq_time)
              Returns the hour component of time.

       htmlescape(s_str)
              Returns a modified copy of str where "<" is replaced with "&lt;"; ">" is replaced with "&gt;"  and
              "&" is replaced with "&amp;"

       htmlstriptags(s_str)
              Returns  a  modified  copy  of  str  where HTML tags are stripped out.  The stripping algorithm is
              fairly naive; the function starts stripping characters when it  encounters  a  "<"  and  it  stops
              stripping when it encounters a ">".

       iif(si_test1, x_arg1, [si_test2, x_arg2,...], x_default)
              If  test1  is  not  zero or the null string, returns arg1.  Otherwise, if test2 is not zero or the
              null string, returns arg2, and so on.  If all of the test arguments are  false,  returns  default.
              Note  that all arguments are always evaluated.  This function accepts an odd number of arguments -
              note that prior to version 03.00.05 of Remind, it  accepted  3  arguments  only.   The  3-argument
              version of iif() is compatible with previous versions of Remind.

       index(s_search, s_target [,i_start)
              Returns  an  INT  that  is  the location of target in the string search.  The first character of a
              string is numbered 1.  If target does not exist in search, then 0 is returned.

              The optional parameter start specifies the position in  search  at  which  to  start  looking  for
              target.

       isany(arg1 [,arg2, ..., argN]);
              Returns  1  if  the  first  argument arg1 is equal to any of the subsequent arguments arg2 through
              argN; returns 0 otherwise.  Also returns 0 if called with only one argument.

              As an example, the following two expressions are equivalent:

                      (a == b) || (a == c) || (a == d) || (a == e)

                      isany(a, b, c, d, e)

       isdst([d_date [,t_time]]) or isdst(q_datetime)
              Returns a positive number if daylight saving time is in effect on the  specified  date  and  time.
              Date defaults to today() and time defaults to midnight.

              Note  that this function is only as reliable as the C run-time library functions.  It is available
              starting with version 03.00.07 of Remind.

       isleap(idq_arg)
              Returns 1 if arg is a leap year, and 0 otherwise.  Arg can be an INT, DATE or DATETIME object.  If
              a DATE or DATETIME is supplied, then the year component is used in the test.

       isomitted(dq_date)
              Returns  1 if date is omitted, given the current global OMIT context.  Returns 0 otherwise.  (If a
              datetime is supplied, only the date part is used.)  Note that any local OMIT or  OMITFUNC  clauses
              are not taken into account by this function.

       language()
              Returns  a STRING naming the language supported by Remind.  (See "SUPPORT FOR OTHER LANGUAGES") By
              default, Remind is compiled to support English messages, so this function returns "English".   For
              other  languages,  this function will return the English name of the language (e.g. "German") Note
              that language() is not available in versions of Remind prior to 03.00.02.

       localtoutc(q_datetime)
              Given a DATETIME object interpreted in  the  local  time  zone,  return  a  DATETIME  object  that
              expresses the same time in UTC.

       lower(s_string)
              Returns a STRING with all upper-case characters in string converted to lower-case.

       max(x_arg1 [,x_arg2...)
              Can  take any number of arguments, and returns the maximum.  The arguments can be of any type, but
              must all be of the same type.  They are compared as with the > operator.

       min(x_arg1 [,x_arg2...)
              Can take any number of arguments, and returns the minimum.  The arguments can be of any type,  but
              must all be of the same type.  They are compared as with the < operator.

       minsfromutc([d_date [,t_time]]) or minsfromutc(q_datetime)
              Returns  the number of minutes from Universal Time Coordinated (formerly GMT) to local time on the
              specified date and time.  Date defaults to today() and time defaults to midnight.  If  local  time
              is before UTC, the result is negative.  Otherwise, the result is positive.

              Note  that this function is only as reliable as the C run-time library functions.  It is available
              starting with version 03.00.07 of Remind.

       minute(tq_time)
              Returns the minute component of time.

       mon(dqi_arg)
              If arg is of DATE or DATETIME type, returns a string that names the month component of  the  date.
              If arg is an INT from 1 to 12, returns a string that names the month.

       monnum(dq_date)
              Returns an INT from 1 to 12, representing the month component of date.

       moondate(i_phase [,d_date [,t_time]]) or moondate(i_phase, q_datetime)
              This  function returns the date of the first occurrence of the phase phase of the moon on or after
              date and time.  Phase can range from 0 to 3, with 0 signifying new moon, 1 first quarter,  2  full
              moon,  and  3  third quarter.  If date is omitted, it defaults to today().  If time is omitted, it
              defaults to midnight.

              For example, the following returns the date of the next full moon:

                        SET fullmoon moondate(2)

       moontime(i_phase [,d_date [,t_time]]) or moontime(i_phase, q_datetime)
              This function returns the time of the first occurrence of the phase phase of the moon on or  after
              date  and  time.  Phase can range from 0 to 3, with 0 signifying new moon, 1 first quarter, 2 full
              moon, and 3 third quarter.  If date is omitted, it defaults to today().  If time  is  omitted,  it
              defaults  to  midnight.   Moontime()  is  intended to be used in conjunction with moondate().  The
              moondate() and moontime() functions are accurate to within a couple of minutes  of  the  times  in
              "Old Farmer's Almanac" for Ottawa, Ontario.

              For example, the following returns the date and time of the next full moon:

                        MSG Next full moon at [moontime(2)] on [moondate(2)]

       moondatetime(i_phase [,d_date [,t_time]]) or moondatetime(i_phase, q_datetime)
              This function is similar to moondate and moontime, but returns a DATETIME result.

       moonphase([d_date [,t_time]]) or moonphase(q_datetime)
              This  function  returns  the  phase  of  the  moon  on date and time, which default to today() and
              midnight, respectively.  The returned value is an integer from 0 to 359, representing the phase of
              the moon in degrees.  0 is a new moon, 180 is a full moon, 90 is first-quarter, etc.

       multitrig(s_trig1 [,s_trig2, [... s_trigN]])
              multitrig  evaluates  each  string  as  a  trigger,  similar to evaltrig, and returns the earliest
              trigger date that is on or after today().  multitrig is similar to  trig  but  has  the  following
              difference:

              trig returns the first trigger date that would have triggered today, whereas multitrig returns the
              earliest trigger date later than today, regardless of whether it would have triggered today.

              If no trigger can be computed that is later than today(), then multitrig returns 1990-01-01.

              Consider the following examples, assuming that today is Sunday, 24 March 2024:

                 # Returns 1990-01-01 because neither would trigger today
                 SET a trig("Mon", "Wed")

                 # Returns 2024-03-25 because it's the earlier trigger date
                 SET a multitrig("Mon", "Wed")

                 # Returns 2024-03-27 because it's the first that would trigger today
                 SET a trig("Wed +3", "Mon +3")

                 # Returns 2024-03-25 because it's the earlier trigger date
                 SET a multitrig("Wed +3", "Mon +3")

                 # Returns 1990-01-01 because all triggers have expired
                 SET a multitrig("2000", "2022", "1998", "2023")

              In general, multitrig works better with the Remind algorithm than trig and should be used most  of
              the time.  As an example, this reminder is issued at the end of each quarter:

                  REM [multitrig("Mar 31", "Jun 30", "Sep 30", "Dec 31")] +7 MSG \
                  %"End of [ord($Tm/3)] quarter%" is %b.

              If you want the last working day of each quarter, you could use:

                  PUSH-OMIT-CONTEXT
                  OMIT Sat Sun
                  REM [multitrig("Mar ~1", "Jun ~1", "Sep ~1", "Dec ~1")] +7 MSG \
                  %"Last working day of [ord($Tm/3)] quarter%" is %b.
                  POP-OMIT-CONTEXT

              Note  that unlike evaltrig, multitrig always returns a DATE and never a DATETIME.  Including an AT
              clause in a trigger supplied to multitrig will result in an error.

       ndawn([dq_date])
              Returns the time of "nautical dawn" on the specified  date.   If  date  is  omitted,  defaults  to
              today().  If a datetime object is supplied, only the date component is used.

       ndusk([dq_date])
              Returns  the  time  of "nautical twilight" on the specified date.  If date is omitted, defaults to
              today().

       nonomitted(dq_start, dq_end [, i_step] [,s_wkday...])
              This function returns the number of non-omitted days between start and  end.   If  start  is  non-
              omitted, then it is counted.  end is never counted.

              Note  that  if  end  is less than start, the arguments are effectively swapped, so counting always
              begins from the older date.

              If the third argument to nonomitted is an INT, then it must be greater than zero, and is  consider
              to be the step by which nonomitted counts.  For example the following expression:

                      nonomitted('2023-07-01', '2023-07-29', 7)

              returns  the number of non-omitted Saturdays from 2023-07-01 up to (but not including) 2023-07-29.
              (Both 2023-07-01 and 2023-07-29 are Saturdays.)

              If no step argument is supplied, then a step of 1 is used.

              In addition to using the global OMIT context, you can supply additional arguments that  are  names
              of weekdays to be omitted.  However, in a REM command, any local OMITFUNC clause is not taken into
              account by this function.

              For example, the following line sets a to 11 (assuming no global OMITs):

                   set a nonomitted('2007-08-01', '2007-08-16', "Sat", "Sun")

              because Thursday, 16 August 2007 is the 11th working day (not counting Saturday and Sunday)  after
              Wednesday, 1 August 2007.

              nonomitted  has various uses.  For example, many schools run on a six-day cycle and the day number
              is not incremented on holidays.  Suppose the school year starts with Day 1 on  4  September  2007.
              The following reminder will label day numbers in a calendar:

                 IF today() >= '2007-09-04'
                     set daynum nonomitted('2007-09-04', today(), "Sat", "Sun")
                     REM OMIT SAT SUN SKIP CAL Day [(daynum % 6) + 1]
                 ENDIF

              Obviously,  the  answer  you  get  from nonomitted depends on the global OMIT context.  If you use
              movable OMITs, you may get inconsistent results.

              Here is a more complex use for nonomitted.  My garbage collection follows two  interleaved  14-day
              cycles:  One  Friday,  garbage  and paper recycling ("Black Box") are collected.  The next Friday,
              garbage and plastic recycling ("Blue Box") are collected.  If any of Monday-Friday is  a  holiday,
              collection is delayed until the Saturday.  Here's a way to encode these rules:

                 fset _garbhol(x) wkdaynum(x) == 5 && nonomitted(x-4, x+1) < 5
                 REM 12 November 1999 *14 AFTER OMITFUNC _garbhol MSG Black Box
                 REM 19 November 1999 *14 AFTER OMITFUNC _garbhol MSG Blue Box

              Here's  how  it  works:  The _garbhol(x) user-defined function returns 1 if and only if (1) x is a
              Friday and (2) there is at least one OMITted day from the previous Monday up to and including  the
              Friday.

              The  first  REM  statement  sets  up  the 14-day black-box cycle.  The AFTER keyword makes it move
              collection to the Saturday if _garbhol returns 1.  The second REM statement  sets  up  the  14-day
              blue-box cycle with a similar adjustment made by AFTER in conjunction with _garbhol.

       now()  Returns  the current system time, as a TIME type.  This may be the actual time, or a time supplied
              on the command line.

       ord(i_num)
              Returns a string that is the ordinal number num.  For example, ord(2) returns "2nd", and  ord(213)
              returns "213th".

       orthodoxeaster([dqi_arg])
              If  arg is an INT, then returns the date of Orthodox Easter Sunday for the specified year.  If arg
              is a DATE or DATETIME, then returns the date of the next Orthodox Easter Sunday on or  after  arg.
              (The time component of a datetime is ignored.)  If arg is omitted, then it defaults to today().

              Note  that  orthodoxeaster  computes  the  Orthodox  Easter.   For  the  Western  Easter date, see
              easterdate.

       ostype()
              Returns "UNIX".  Remind used to run on OS/2 and MS-DOS, but does not any longer.

       pad(x_arg, s_padstr, i_len [, i_right])
              Converts the first argument arg to a string if necessary, and then  if  it  is  shorter  than  len
              characters, pads to to len characters using as many copies (including partial copies) of padstr as
              necessary.  By default, the string is left-padded, but if right  is  supplied  and  non-zero,  the
              string will be right-padded.

              Here are some examples:

                  pad(3, "0", 2)        -->  "03"
                  pad(465, "0", 2)      -->  "465"
                  pad("foo", " ", 5)    -->  "  foo"
                  pad("foo", " ", 5, 1) -->  "foo  "
                  pad("foo", "bar", 11) -->  "barbarbafoo"

       plural(i_num [,s_str1 [,s_str2]])
              Can  take  from one to three arguments.  If one argument is supplied, returns "s" if num is not 1,
              and "" if num is 1.

              If two arguments are supplied, returns str1 + "s" if num is not 1.  Otherwise, returns str1.

              If three arguments are supplied, returns str1 if num is 1, and str2 otherwise.

       psmoon(i_phase [,i_size [,s_note [,i_notesize]]])
              [DEPRECATED] Returns a STRING consisting of PostScript code to draw a moon in the upper-left  hand
              corner  of the calendar box.  Phase specifies the phase of the moon, and is 0 (new moon), 1 (first
              quarter), 2 (full moon) or 3 (third quarter).  If size is specified, it controls the radius of the
              moon in PostScript units (1/72 inch.)  If it is not specified or is negative, the size of the day-
              number font is used.

              For example, the following four lines place moon symbols on the PostScript calendar:

                        REM [moondate(0)] PS [psmoon(0)]
                        REM [moondate(1)] PS [psmoon(1)]
                        REM [moondate(2)] PS [psmoon(2)]
                        REM [moondate(3)] PS [psmoon(3)]

              If note is specified, the text is used to annotate the moon display.  The font is  the  same  font
              used  for  calendar  entries.   If  notesize  is  given, it specifies the font size to use for the
              annotation, in PostScript units (1/72 inch.)  If notesize is not given, it defaults  to  the  size
              used  for  calendar  entries.   (If  you annotate the display, be careful not to overwrite the day
              number -- Remind does not check for this.)  For example, if you want the time  of  each  new  moon
              displayed, you could use this in your reminder script:

                   REM [moondate(0)] PS [psmoon(0, -1, moontime(0)+"")]

              Note how the time is coerced to a string by concatenating the null string.

       psshade(i_gray) or psshade(i_red, i_green, i_blue)
              [DEPRECATED]  Returns  a STRING that consists of PostScript commands to shade a calendar box.  Num
              can range from 0 (completely black) to 100 (completely white.)  If three arguments are given, they
              specify red, green and blue intensity from 0 to 100.  Here's an example of how to use this:

                        REM Sat Sun PS [psshade(95)]

              The  above  command  emits PostScript code to lightly shade the boxes for Saturday and Sunday in a
              PostScript calendar.

              Note that psmoon and psshade are deprecated; instead you should use the SPECIAL SHADE and  SPECIAL
              MOON reminders as described in "Out-of-Band Reminders."

       realcurrent()
              Returns  (as  a DATETIME) the true date and time of day as provided by the operating system.  This
              is in contrast to current(), which may return a time supplied on the command line.

       realnow()
              Returns the true time of day as provided by the operating system.  This is in contrast  to  now(),
              which may return a time supplied on the command line.

       realtoday()
              Returns  the date as provided by the operating system.  This is in contrast to Remind's concept of
              "today", which may be changed if it is running in calendar mode, or if a date has been supplied on
              the command line.

       rows() If  standard  output  is a TTY, returns the height of the terminal in rows.  If standard output is
              not a TTY, attempts to open "/dev/tty" to obtain the terminal size.  If this fails, returns -1.

       sgn(i_num)
              Returns -1 if num is negative, 1 if num is positive, and 0 if num is zero.

       shell(s_cmd [,i_maxlen])
              Executes cmd as a system command, and returns the first 511 characters of  output  resulting  from
              cmd.   Any  whitespace  character in the output is converted to a space.  Note that if RUN OFF has
              been executed, or the -r command-line option has been used, shell() will result in an  error,  and
              cmd will not be executed.

              If  maxlen  is  specified, then shell() returns the first maxlen characters of output (rather than
              the first 511).  If maxlen is specified as a negative number, then it defaults to the value of the
              system variable $MaxStringLen.

       shellescape(s_str)
              Returns  str  with  all  shell metacharacters such as " ", "*", etc escaped with a backslash.  For
              example:

               SET a shellescape("a b*? c&d$e")

              will set a to:

               "a\ b\*\?\ c\&d\$e"

       slide(d_start, i_amt [, i_step] [,s_wkday...])
              This function is the inverse of nonomitted.  It adds amt (which can be negative)  chunks  of  step
              days  to  start,  not counting omitted days.  If step is not supplied, then it is assumed to be 1.
              Note that only every stepth day is tested to see if it is omitted.  The optional  wkday  arguments
              are additional weekday names to omit.

              Consider this example:

                   OMIT 14 May 2009
                   SET a slide('2009-05-13', 5, "Sat", "Sun")

              In  this  case,  a is set to 2009-05-21.  That's because we slide forward by 5 days, not including
              Thursday, May 14 or Saturday and Sunday, May 16 and 17.  You can go backwards, too, so:

                   OMIT 14 May 2009
                   SET a slide('2009-05-21', -5, "Sat", "Sun")

              takes a back to 2009-05-13.

              Now consider this example:

                      OMIT 14 May 2009
                      SET a slide('2009-05-07', 2, 7)

              This sets a to '2009-05-28' because we skip ahead two weeks, not counting a week where the day  we
              land on happens to be omitted.  Contrast with this:

                      OMIT 13 May 2009
                      SET a slide('2009-05-07', 2, 7)

              which  sets  a  to '2009-05-21'.  Although 2009-05-13 is omitted, we don't "land" on it as we step
              forward in chunks of 7 days, so we never see that it is omitted.

       soleq(i_which [, dqi_start])
              The soleq function computes solstices and equinoxes.  The which parameter ranges from 0 to 3,  and
              specifies  which  event we are interested in: 0 is the March equinox; 1 is the June solstice; 2 is
              the September equinox and 3 is the December solstice.

              The optional start parameter can either be an integer specifying the year  of  the  event  we  are
              interested  in, or a DATE or DATETIME object; if the latter, then soleq returns the first event on
              or after the date part of the start parameter (it  ignores  the  time  component  if  start  is  a
              DATETIME.)  If start is not supplied, then it defaults to today().

              The  return  value of soleq() is a DATETIME object specifying the date and time of the solstice or
              equinox in the local time zone.  It should be accurate to within 3 minutes  or  so  in  the  worst
              case.

              See the included file $SysInclude/seasons.rem for examples of how to use soleq().

       stdout()
              Returns  a string representing where Remind's standard output is going.  The return values are one
              of the following: "TTY" if standard-output is a terminal, "BLOCKDEV" if it is a block device (very
              unlikely), "CHARDEV" if it is a character device (eg, /dev/null), "DIR" if it is a directory (very
              unlikely), "PIPE" if it is a pipe or FIFO, "SYMLINK" if it is a symlink (very unlikely),  "SOCKET"
              if it is a socket, or "UNKNOWN" if it could not be determined.

              The  purpose  of stdout() is mostly to distinguish between TTY and non-TTY output; you may wish to
              change or disable colors if the output is not going to a TTY.

       strlen(s_str)
              Returns the length of str.  If the length of str is too large to represent as an integer, emits  a
              "Number too high" error.

       substr(s_str, i_start [,i_end])
              Returns  a  STRING  consisting  of  all  characters  in  str  from  start up to and including end.
              Characters are numbered from 1.  If end is not supplied, then it defaults to the length of str.

       sunrise([dq_date])
              Returns a TIME indicating the time of sunrise on the specified date (default  today().)   In  high
              latitudes,  there may be no sunrise on a particular day, in which case sunrise() returns the INT 0
              if the sun never sets, or 1440 if it never rises.

       sunset([dq_date])
              Returns a TIME indicating the time of sunset on the specified date  (default  today().)   In  high
              latitudes, there may be no sunset on a particular day, in which case sunset() returns the INT 0 if
              the sun never rises, or 1440 if it never sets.

              The functions sunrise() and sunset() are based on an algorithm in "Almanac for Computers  for  the
              year  1978"  by  L.  E.  Doggett,  Nautical  Almanac  Office, USNO.  They require the latitude and
              longitude to be specified by setting the appropriate system variables.  (See "System  Variables".)
              The  sun  functions  should  be  accurate  to  within  about 4 minutes for latitudes lower than 60
              degrees.  The functions are available starting from version 03.00.07 of Remind.

       time(i_hr, i_min)
              Creates a TIME with the hour and minute components specified by hr and min.

       timepart(tq_datetime)
              Returns a TIME object representing the time portion of datetime.

       timezone([dq_datetime])
              Returns a string representing the local time zone name of the given DATETIME.  If no  argument  is
              supplied,  Remind uses the value of current().  If a DATE rather than DATETIME is supplied, Remind
              uses a time part of 00:00.

       today()
              Returns Remind's notion of "today."  This may be the actual system date, or a date supplied on the
              command line, or the date of the calendar entry currently being computed.

       trig(s_1 [,s_2, ...])
              For  each  string  argument  s_n,  trig  evaluates  s_n  as  if  it  were  a REM or IFTRIG trigger
              specification.  If the trigger would trigger today, then the  trigger  date  is  returned  and  no
              further  triggers  are evaluated.  If none of the triggers would trigger today, then the zero date
              1990-01-01 is returned.
              trig also has a zero-argument form; this returns the trigger date of the most recent trig function
              that returned a non-zero trigger date.

              trig can be used to make more sophisticated versions of IFTRIG.  For example, if you have meetings
              every Monday in June and July, and you want warnings 3 days in advance, you could use:

                  REM [trig("Mon Jun +3", "Mon July +3")] +3 MSG Meeting %b

              NOTE: We need to repeat the +3 delta outside of the trig function  for  advance  warning  to  work
              properly.   This  is  because  trig returns a date constant (the trigger date) and the REM command
              does not know the details of trig's arguments.

              Note that because Remind has short-circuit logical operators, something like:

                  SET a trig("Mon +7") || trig("Fri +7")

              would set the value of trig() to the date of the following Monday.  Because trig("Mon +7")  always
              returns  true,  the  logical-OR operator does not bother evaluating trig("Fri +7") which therefore
              does not set trig().

              Important Note:  Because trig() always returns an absolute date, it will not work properly with  a
              SATISFY clause.  Consider this reminder:

                  REM [trig("Mar", "Apr")] SATISFY [$Td == 15] MSG 15 Mar or April

              If  we  run  Remind on 5 March 2022, we might expect the trigger date to be calculated as 15 March
              2022... but that's not what happens.  Instead, the  trig  function  is  evaluated  first,  and  it
              returns 2022-03-05.  So as far as Remind is concerned, the REM statement becomes:

                  REM 2022-03-05 SATISFY [$Td == 15] MSG 15 Mar or April

              and the SATISFY expression is never true.  So: Do not mix trig() and SATISFY.

       trigdate()
              Returns  the  calculated trigger date of the last REM or IFTRIG command.  If used in the body of a
              REM command, returns that command's trigger date.  If the most recent REM command did not yield  a
              computable trigger date, returns the integer 0.

       trigdatetime()
              Similar to trigdate(), but returns a DATETIME if the most recent triggerable REM command had an AT
              clause.  If there was no AT clause, returns a DATE.  If no trigger could be computed, returns  the
              integer 0.  See "MULTI-DAY EVENTS" for more information.

       trigeventstart()
              Returns  a  DATETIME representing the start of the most recent triggerable REM command that had an
              AT clause.  For events without a DURATION or that do not span multiple days, returns the  same  as
              trigdatetime().  If the REM command did not have an AT clause, returns the integer -1 (and differs
              from trigdatetime() in this respect.)  See "MULTI-DAY EVENTS" for more information.

       trigeventduration()
              Returns a TIME representing the duration of the most recent triggerable REM command that had an AT
              and  a  DURATION  clause.   If  the  event  does not span multiple days, returns the same thing as
              trigduration().  If the REM command lacked an AT or DURATION clause, returns -1.   See  "MULTI-DAY
              EVENTS" for more information.

       trigback()
              Returns  the "back" amount of the last REM or IFTRIG command.  Returns a positive integer N if the
              "back" is of the form -N, or a negative integer if it is of the form --N.  If there is no  "back",
              then returns 0.

       trigdelta()
              Returns the "delta" amount of the last REM or IFTRIG command.  Returns a positive integer N if the
              "delta" is of the form +N, or a negative integer if it is  of  the  form  ++N.   If  there  is  no
              "delta", then returns 0.

       trigtimedelta()
              Similar to trigdelta(), but returns the delta used in the AT clause of a timed reminder.

       trigrep()
              Returns  the  "repeat"  amount of the last REM or IFTRIG command.  Returns a positive integer N if
              the "repeat" is of the form *N.  If there is no "repeat", then returns 0.

       trigtimerep()
              Similar to trigrep(), but returns the repeat used in the AT clause of a timed reminder.

       trigduration()
              Returns (as a TIME type) the DURATION parameter of a timed reminder.   If  there  is  no  DURATION
              parameter, returns the integer -1.  See "MULTI-DAY EVENTS" for more information.

       trigpriority()
              Returns the PRIORITY of the last REM or IFTRIG command.

       triguntil()
              Returns  (as  a DATE type) the UNTIL parameter of the last REM or IFTRIG command.  If there was no
              UNTIL parameter, returns the integer -1.  If there is a THROUGH parameter, that will  be  returned
              by triguntil() since "THROUGH yyyy-mm-dd" is simply syntactic sugar for "*1 UNTIL yyyy-mm-dd".

       trigscanfrom()
              Returns  (as  a DATE type) the SCANFROM parameter of the last REM or IFTRIG command.  If there was
              no SCANFROM parameter, returns the integer -1.  Note that FROM and SCANFROM interact;  a  reminder
              that  has  a "FROM yyyy-mm-dd" parameter will act as if it has a SCANFROM parameter whose value is
              the maximum of "yyyy-mm-dd" and today.

       trigfrom()
              Returns (as a DATE type) the FROM parameter of the last REM or IFTRIG command.  If  there  was  no
              FROM parameter, returns the integer -1.

       trigger(d_date [,t_time [,i_utcflag]]) or trigger(q_datetime [,i_utcflag])
              Returns  a string suitable for use in a REM command or a SCANFROM or UNTIL clause, allowing you to
              calculate trigger dates in advance.  Note that in earlier versions of Remind, trigger was required
              to  convert  a  date  into  something  the REM command could consume.  However, in this version of
              Remind, you can omit it.  Note that trigger() always returns its result in English, even for  non-
              English  versions of Remind.  Normally, the date and time are the local date and time; however, if
              utcflag is non-zero, the date and time are interpreted as UTC times, and are  converted  to  local
              time.  Examples:

                   trigger('1993/04/01')

              returns "1 April 1993",

                   trigger('1994/08/09', 12:33)

              returns "9 August 1994 AT 12:33", as does:

                   trigger('1994/08/09@12:33').

              Finally:

                   trigger('1994/12/01', 03:00, 1)

              returns "30 November 1994 AT 22:00" for EST, which is 5 hours behind UTC.  The value for your time
              zone may differ.

       trigtags()
              Returns a comma-separated list of the TAGs associated with the most recent REM  command  that  was
              triggered.   Returns the empty string if there were no TAGs.  If there are multiple tags, they are
              each separated by a single comma, not a comma and a space.

       trigtime()
              Returns the time of the last REM command with an AT clause.  If the last REM did not  have  an  AT
              clause,  returns  the  integer 0.  If a REM command has an AT clause with a DURATION, then you can
              compute the end time as trigtime() + trigduration().

       trigvalid()
              Returns 1 if the value returned by trigdate() is valid for the  most  recent  REM  command,  or  0
              otherwise.   Sometimes  REM  commands cannot calculate a trigger date.  For example, the following
              REM command can never be triggered:

                 REM Mon OMIT Mon SKIP MSG Impossible!

       typeof(x_arg)
              Returns "STRING", "INT", "DATE", "TIME" or "DATETIME", depending on the type of arg.

       tzconvert(q_datetime, s_srczone [,s_dstzone])
              Converts datetime from the time zone named by srczone to the  time  zone  named  by  dstzone.   If
              dstzone  is  omitted, the default system time zone is used.  The return value is a DATETIME.  Time
              zone names are system-dependent; consult your operating system  for  legal  values.   Here  is  an
              example:

           tzconvert('2007-07-08@01:14', "Canada/Eastern", "Canada/Pacific")

                 returns

           2007-07-07@22:14

       upper(s_string)
              Returns a STRING with all lower-case characters in string converted to upper-case.

       utctolocal(q_datetime)
              Given  a DATETIME object interpreted in UTC, return a DATETIME object that expresses the same time
              in the local time zone.

       value(s_varname [,x_default])
              Returns the value of the specified variable.  For example, value("X"+"Y")  returns  the  value  of
              variable XY, if it is defined.  If XY is not defined, an error results.

              However,  if  you  supply  a  second  argument, it is returned if the varname is not defined.  The
              expression value("XY", 0) will return 0 if XY is not defined,  and  the  value  of  XY  if  it  is
              defined.

       version()
              Returns  a string specifying the version of Remind.  For version 05.00.02, returns "05.00.02".  It
              is guaranteed that as new versions of Remind are released, the value returned  by  version()  will
              strictly increase, according to the rules for string ordering.

       weekno([dq_date, [i_wkstart, [i_daystart]]])
              Returns  the  week  number  of  the year.  If no arguments are supplied, returns the ISO 8601 week
              number for today().  If one argument date is supplied, then returns the ISO 8601 week  number  for
              that date.  If two arguments are supplied, then wkstart must range from 0 to 6, and represents the
              first day of the week (with 0 being Sunday and 6 being Saturday.).  If wkstart  is  not  supplied,
              then  it defaults to 1.  If the third argument daystart is supplied, then it specifies when Week 1
              starts.  If daystart is less than or equal to 7, then Week 1 starts on the  first  wkstart  on  or
              after  January  daystart.   Otherwise,  Week  1  starts  on the first wkstart on or after December
              daystart.  If omitted, daystart defaults to 29 (following the ISO 8601 definition.)

       wkday(dqi_arg)
              If arg is a DATE or DATETIME, returns a string representing the day of the week of the  date.   If
              arg is an INT from 0 to 6, returns the corresponding weekday ("Sunday" to "Saturday").

       wkdaynum(dq_date)
              Returns  a  number  from 0 to 6 representing the day-of-week of the specified date.  (0 represents
              Sunday, and 6 represents Saturday.)

       year(dq_date)
              Returns a INT that is the year component of date.

MULTI-DAY EVENTS

       If you specify a start time with AT and a duration  with  DURATION,  you  can  create  events  that  span
       multiple days.  Consider these two REM statements:

           REM 1991-02-13 AT 16:00 DURATION 72:00 MSG 72-hour event
           REM 1991-02-13 THROUGH 1991-02-16 AT 16:00 MSG Four events

       The  first  statement creates a single event that starts on 13 February 1991 at 16:00 and runs through 16
       February 1991 at 16:00

       The second statements creates four separate events that start at 16:00 on 13, 14, 15 and 16 February 1991
       and have indefinite duration.

       Remind handles multi-day events specially.  These are the rules:

       On  the  first  day  of  a  multi-day event, trigdatetime() will return the starting date and time of the
       event, and trigduration() will return the original DURATION.

       On each subsequent day of a multi-day event, trigdatetime() will return midnight on the day in  question,
       and trigduration() will return the remaining duration.  Consider this example:

           #!/bin/sh
           remind - 12 feb 1991 '*6' <<'EOF'
           BANNER %
           REM 1991-02-13 AT 16:00 DURATION 72:00 SATISFY 1
           set a trigdatetime()
           set b trigduration()
           set c trigeventstart()
           set d trigeventduration()
           MSG now=[today()] dt=[a] dur=[b] estart=[c] edur=[d]%
           EOF

       The output is:

       now=1991-02-12 dt=1991-02-13@16:00 dur=72:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-13 dt=1991-02-13@16:00 dur=72:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-14 dt=1991-02-14@00:00 dur=64:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-15 dt=1991-02-15@00:00 dur=40:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-16 dt=1991-02-16@00:00 dur=16:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-17 dt=1991-02-13@16:00 dur=72:00 estart=-1 edur=-1

       As  you  see,  the  trigdatetime() and trigduration() functions return the start time and duration of the
       remaining portion of a multi-day event, whereas trigeventstart and trigeventduration  always  return  the
       original  start  and  duration  of  the  multi-day  event.   Note  also that the return value for expired
       reminders is not reliable; the fact that trigeventstart and trigeventduration return -1 in that  case  is
       an implementation artifact.

       SELF-OVERLAPPING EVENTS

       A  multi-day  event  has  the possibility of "overlapping itself".  When this happens, Remind prefers the
       later event (only one copy of an event is ever triggered for a given date.)  Consider this example:

          #!/bin/sh
          remind - '*5' 10 Feb 1991 <<'EOF'

          BANNER %
          REM MON at 0:00 DURATION 192:0 MSG [today()] [trigeventstart()] [trigduration()]%

          EOF

       The output is:

          1991-02-10 1991-02-04@00:00 48:00
          1991-02-11 1991-02-11@00:00 192:00
          1991-02-12 1991-02-11@00:00 168:00
          1991-02-13 1991-02-11@00:00 144:00
          1991-02-14 1991-02-11@00:00 120:00

       Although the event from 1991-02-04 still has 24  hours  left  on  1991-02-11,  the  fresh  occurrence  on
       1991-02-11 takes precedences and is the one that is triggered.

       I do not recommend constructing self-overlapping multi-day events.

EXPRESSION PASTING

       An extremely powerful feature of Remind is its macro capability, or "expression pasting."

       In  almost  any  situation where Remind is not expecting an expression, you can "paste" an expression in.
       To do this, surround the expression with square brackets.  For example:

            REM [mydate] MSG foo

       This evaluates the expression "mydate", where "mydate" is presumably some pre-computed variable, and then
       "pastes" the result into the command-line for the parser to process.

       If you want a literal "[" character for some reason, simply use "[[".  For example:

               REM MSG Here are [[square] brackets!

       A  formal  description  of  this  is:   When Remind encounters a "pasted-in" expression, it evaluates the
       expression, and coerces the result to a STRING.   It  then  substitutes  the  string  for  the  pasted-in
       expression,  and  continues  parsing.   Note,  however,  that  expressions  are  evaluated only once, not
       recursively.  Thus, writing:

            ["[a+b]"]

       causes Remind to read the token "[a+b]".  It does not interpret this as a pasted-in expression.  In fact,
       the only way to get a literal left-bracket into a reminder is to use ["["].

       You can use expression pasting almost anywhere.  However, there are a few exceptions:

       o      If  Remind  is  expecting  an expression, as in the SET command, or the IF command, you should not
              include square brackets.  For example, use:

                 SET a 4+5
       and not:
                 SET a [4+5]

       o      You cannot use expression pasting for the first token on a line.  For example, the following  will
              not work:

                 ["SET"] a 1

              This  restriction  is  because Remind must be able to unambiguously determine the first token of a
              line for the flow-control commands (to be discussed later.)

              In fact, if Remind cannot determine the first token on a  line,  it  assumes  that  it  is  a  REM
              command.   If expression-pasting is used, Remind assumes it is a REM command.  Thus, the following
              three commands are equivalent:

                        REM 12 Nov 1993 AT 13:05 MSG BOO!
                        12 Nov 1993 AT 13:05 MSG BOO!
                        [12] ["Nov " + 1993] AT [12:05+60] MSG BOO!

       o      You cannot use expression-pasting to determine the type (MSG, CAL, etc.) of a  REM  command.   You
              can paste expressions before and after the MSG, etc. keywords, but cannot do something like this:

                      REM ["12 Nov 1993 AT 13:05 " + "MSG" + " BOO!"]

              However,  as  an  escape  hatch, the sequence SPECIAL type means the same thing as just type where
              type is one of MSG, MSF, RUN, CAL, PS and PSFILE.  This lets you do something like this:

                      SET type "MSG"
                      REM 12 Nov 2024 SPECIAL [type] Hello

              You can use this to control the types of your reminders based on variables you set, how Remind  is
              invoked, etc.

       COMMON PITFALLS WITH EXPRESSION PASTING

       Remember that extra spaces are not inserted when an expression is pasted.  Thus, something like:

            REM[expr]MSG[expr]

       will probably fail.

       If  you  use  an  expression  to  calculate a delta or back, ensure that the result is a positive number.
       Something like:

            REM +[mydelta] Nov 12 1993 MSG foo

       will fail if mydelta happens to be negative.

FLOW CONTROL COMMANDS

       Remind has commands that control the flow of a reminder script.  Normally, reminder scripts are processed
       sequentially.   However,  IF  and  related  commands  allow  you to process files conditionally, and skip
       sections that you don't want interpreted.

       THE IF COMMAND

       The IF command has the following form:

            IF expr
                 t-command
                 t-command...
            ELSE
                 f-command
                 f-command...
            ENDIF

       Note that the commands are shown indented for clarity.  Also,  the  ELSE  portion  can  be  omitted.   IF
       commands  can be nested up to a small limit, probably around 8 or 16 levels of nesting, depending on your
       system.

       If the expr evaluates to a non-zero INT, a DATE that is not 1990-01-01, a  TIME  that  is  not  00:00,  a
       DATETIME  that is not 1990-01-01@00:00, or a non-null STRING, then the IF portion is considered true, and
       the t-commands are executed.  If expr evaluates to zero or null, then the f-commands (if the ELSE portion
       is present) are executed.

       Examples:

            IF defined("want_hols")
                 INCLUDE /usr/share/remind/holidays
            ENDIF

            IF today() > '1992/2/10'
                 set missed_ap "You missed it!"
            ELSE
                 set missed_ap "Still have time..."
            ENDIF

       THE IFTRIG COMMAND

       The  IFTRIG  command  is  similar  to  an  IF  command,  except that it computes a trigger (as in the REM
       command), and evaluates to true if a corresponding REM command would trigger.  Examples:

            IFTRIG 1 Nov
                 ; Executed on 1 Nov
            ELSE
                 ; Executed except on 1 Nov
            ENDIF

            IFTRIG 1 -1 OMIT Sat Sun +4
                 ; Executed on last working day of month,
                 ; and the 4 working days preceding it
            ELSE
                 ; Executed except on above days
            ENDIF

       Note that the IFTRIG command computes a  trigger  date,  which  can  be  retrieved  with  the  trigdate()
       function.   You  can  use  all of the normal trigger components, such as UNTIL, delta, etc. in the IFTRIG
       command.  However, you cannot use a type specifier such as CAL, MSG  or  SATISFY;  attempting  to  do  so
       yields a parse error.

USER-DEFINED FUNCTIONS

       In  addition to the built-in functions, Remind allows you to define your own functions.  The FSET command
       does this for you:

       FSET fname(args) expr

       Fname is the name of the function, and follows the convention for naming variables.   Args  is  a  comma-
       separated  list  of  arguments, and expr is an expression.  Args can be empty, in which case you define a
       function taking no parameters.  Here are some examples:

            FSET double(x) 2*x
            FSET yeardiff(date1, date2) year(date1) - year(date2)
            FSET since(x) ord($Ty - x)

       The last function is useful in birthday reminders.  For example:

            REM 1 Nov +12 MSG Dean's [since(1984)] birthday is %b.

       Dean was born in 1984.  The above example, on 1 November 1992, would print:

            Dean's 8th birthday is today.

       Similarly, the function is useful in anniversary reminders.  For example:

               REM 4 June MSG [since(1989)] anniversary of the Tienanmen Square massacre

       Notes:

       o      If you access a variable in expr that is not in the list of arguments, the global value  (if  any)
              is used.

       o      Function and parameter names are significant to 64 characters.

       o      The  value() function always accesses the global value of a variable, even if it has the same name
              as an argument.  For example:

                        fset func(x) value("x")
                        set x 1
                        set y func(5)

              The above sequence sets y to 1, which is the global value of x.

       o      User-defined functions may call other functions, including other user-defined functions.  However,
              recursive calls are not allowed.

       o      User-defined functions are not syntax-checked when they are defined; parsing occurs only when they
              are called.

       o      If a user-defined function has the same name as a built-in function, it is ignored and the  built-
              in  function  is used.  To prevent conflicts with future versions of Remind (which may define more
              built-in functions), you may wish to name all user-defined functions beginning with an underscore.

       To delete a user-defined function, use  FUNSET.   This  takes  a  space-separated  list  of  user-defined
       functions to delete.  For example, after the command:

               FUNSET myfunc1 otherfunc thirdfunc

       it is guaranteed that no user-defined functions named myfunc1, otherfunc or thirdfunc will exist.  Remind
       does not issue an error if you try to FUNSET a nonexistent user-defined function; it simply does  nothing
       in that case.

PRECISE SCHEDULING

       The  WARN  keyword  allows  precise control over advance warning in a more flexible manner than the delta
       mechanism.  It should be followed by the name of a user-defined function, warn_function.

       If a warn_function is supplied, then it must take one argument of type INT.  Remind  ignores  any  delta,
       and instead calls warn_function successively with the arguments 1, 2, 3, ...

       Warn_function's return value n is interpreted as follows:

       o      If n is positive, then the reminder is triggered exactly n days before its trigger date.

       o      If n is negative, then it is triggered n days before its trigger date, not counting OMITted days.

       As  an  example,  suppose you wish to be warned of American Independence Day 5, 3, and 1 days in advance.
       You could use this:

            FSET _wfun(x) choose(x, 5, 3, 1, 0)
            REM 4 July WARN _wfun MSG American Independence Day is %b.

       NOTES

       1      If an error occurs during the evaluation of warn_function, then Remind stops calling it and simply
              issues the reminder on its trigger date.

       2      If  the  absolute-values  of  the return values of warn_function are not monotonically decreasing,
              Remind stops calling it and issues the reminder on its trigger date.

       3      Warn_function should (as a matter of good style) return 0 as the final value in  its  sequence  of
              return  values.   However,  a reminder will always be triggered on its trigger date, regardless of
              what warn_function does.

       Similarly to WARN, the SCHED keyword allows precise control over the scheduling of timed  reminders.   It
       should be followed by the name of a user-defined function, sched_function.

       If  a scheduling function is supplied, then it must take one argument of type INT.  Rather than using the
       AT time, time delta, and time repeat, Remind calls the scheduling function to determine when  to  trigger
       the  reminder.  The first time the reminder is queued, the scheduling function is called with an argument
       of 1.  Each time the reminder is triggered, it is re-scheduled by calling the scheduling function  again.
       On each call, the argument is incremented by one.

       The  return  value  of  the scheduling function must be an INT or a TIME.  If the return value is a TIME,
       then the reminder is re-queued to trigger at that time.  If it is a positive integer n, then the reminder
       is  re-queued  to  trigger  at  the  previous  trigger time plus n minutes.  Finally, if it is a negative
       integer or zero, then the reminder is re-queued to trigger n minutes before the AT time.  Note that there
       must be an AT clause for the SCHED clause to do anything.

       Here's an example:

            FSET _sfun(x) choose(x, -60, 30, 15, 10, 3, 1, 1, 1, 1, 0)
            REM AT 13:00 SCHED _sfun MSG foo

       The  reminder  would  first be triggered at 13:00-60 minutes, or at 12:00.  It would next be triggered 30
       minutes later, at 12:30.  Then, it would be triggered at 12:45, 12:55, 12:58,  12:59,  13:00,  13:01  and
       13:02.

       NOTES

       1      If  an  error occurs during the evaluation of sched_func, then Remind reverts to using the AT time
              and the delta and repeat values, and never calls sched_func again.

       2      If processing sched_func yields a time earlier than the current  system  time,  it  is  repeatedly
              called with increasing argument until it yields a value greater than or equal to the current time.
              However, if the sequence of values calculated during the repetition is  not  strictly  increasing,
              then Remind reverts to the default behaviour and never calls sched_func again.

       3      It  is  quite  possible  using  sched_func  to  keep triggering a reminder even after the AT-time.
              However, it is not possible to  reschedule  a  reminder  past  midnight  -  no  crossing  of  date
              boundaries  is  allowed.  Also, it is quite possible to not trigger a reminder on the AT time when
              you use a scheduling function.  However, if your scheduling function is terminated (for reasons  1
              and  2)  before  the  AT time of the reminder, it will be triggered at the AT time, because normal
              processing takes over.

       4      Your scheduling functions should (as a matter of good style) return 0 when no more  scheduling  is
              required.  See the example.

       5      All  scheduling  functions  are  evaluated  after  the  entire Remind script has been read in.  So
              whatever function definitions are in effect at the end of the script are used.

THE SATISFY CLAUSE

       The form of REM that uses SATISFY is as follows:

       REM trigger SATISFY expr

       The way this works is as follows:  Remind first calculates a trigger date, in the normal fashion.   Next,
       it  sets  trigdate()  to  the calculated trigger date.  It then evaluates expr.  If the result is not the
       null string or zero, processing ends.  Otherwise, Remind computes the next  trigger  date,  and  re-tests
       expr.   This  iteration  continues  until  expr evaluates to non-zero or non-null, or until the iteration
       limit specified with the -x command-line option is reached.

       If expr is not satisfied, then trigvalid() is set to 0 and the error message "Can't compute  trigger"  is
       issued.  Otherwise, trigvalid() is set to 1.

       This  is  really  useful  only if expr involves a call to the trigdate() or related functions; otherwise,
       expr will not change as Remind iterates.

       An example of the usefulness of SATISFY:  Suppose you wish to be warned of every Friday the  13th.   Your
       first attempt may be:

            # WRONG!
            REM Fri 13 +2 MSG Friday the 13th is %b.

       But this won't work.  This reminder triggers on the first Friday on or after the 13th of each month.  The
       way to do it is with a more complicated sequence:

            REM 13 SATISFY wkdaynum(trigdate()) == 5
            IF trigvalid()
                 REM [trigdate()] +2 MSG \
                 Friday the 13th is %b.
            ENDIF

       You can write the REM statement a little more concisely:

            REM 13 SATISFY $Tw == 5

       Let's see how this works.  The SATISFY clause iterates through all the 13ths of successive months,  until
       a  trigger  date  is  found  whose  day-of-week  is Friday (== 5).  If a valid date was found, we use the
       calculated trigger date to set up the next reminder.

       We could also have written:

            REM Fri SATISFY day(trigdate()) == 13

       but this would result in more iterations, since "Fridays" occur more often than "13ths of the month."

       Here is another example: Suppose you want to be reminded of something on  the  15th  of  January,  April,
       July, and October.  You could make four separate reminders, or you could use:

               REM 15 SATISFY [isany($Tm, 1, 4, 7, 10)] MSG 15th Reminder!

       This  technique  of  using  one  REM command to calculate a trigger date to be used by another command is
       quite powerful.  For example, suppose you wanted to OMIT  Labour  day,  which  is  the  first  Monday  in
       September.  You could use:

            # Note: SATISFY 1 is an idiom for "do nothing"
            REM Mon 1 Sept SATISFY 1
            OMIT [trigdate()]

       CAVEAT: This only omits the next Labour Day, not all Labour Days in the future.  This could cause strange
       results, as the OMIT context can change depending on the current date.   For  example,  if  you  use  the
       following command after the above commands:

            REM Mon AFTER msg hello

       the result will not be as you expect.  Consider producing a calendar for September, 1992.  Labour Day was
       on Monday, 7 September, 1992.  However, when Remind gets around to calculating the trigger for Tuesday, 8
       September,  1992,  the OMIT command will now be omitting Labour Day for 1993, and the "Mon AFTER" command
       will not be triggered.  (But see the description of  SCANFROM  in  the  section  "DETAILS  ABOUT  TRIGGER
       COMPUTATION.")

       It  is  probably  best  to  stay away from computing OMIT trigger dates unless you keep these pitfalls in
       mind.

       For versions of Remind starting from 03.00.07, you can include a MSG,  RUN,  etc.  clause  in  a  SATISFY
       clause as follows:

            REM trigger_stuff SATISFY [expr] MSG body

       Note  that  for this case only, the expr after SATISFY must be enclosed in square brackets.  It must come
       after all the other components of the trigger, and immediately before the MSG,  RUN,  etc.  keyword.   If
       expr cannot be satisfied, then the reminder is not triggered.

       Thus, the "Friday the 13th" example can be expressed more compactly as:

            REM 13 +2 SATISFY [$Tw == 5] MSG Friday the 13th is %b.

       And you can trigger a reminder on Mondays, Wednesdays and Thursdays occurring on odd-numbered days of the
       month with the following:

            REM Mon Wed Thu SATISFY [$Td %2 ] MSG Here it is!!!

       Note that SATISFY and OMITFUNC can often be used to solve the same problem,  though  in  different  ways.
       Sometimes a SATISFY is cleaner and sometimes an OMITFUNC; experiment and use whichever seems clearer.

POSSIBLY-UNCOMPUTABLE TRIGGERS

       Occasionally,  you  may  wish  to suppress the "Can't compute trigger" warnings for reminders for which a
       trigger date cannot be computed.  For example, the following reminder is triggered on a  Monday  that  is
       not a holiday if the following Tuesday is a holiday:

               REM Mon SKIP SATISFY [isomitted($T+1)] MSG Work between holidays

       However,  if  there  are  no Mondays after today's date that satisfy the condition, Remind will print the
       "Can't compute trigger" error.  To suppress this, use the MAYBE-UNCOMPUTABLE keyword:

               REM MAYBE-UNCOMPUTABLE Mon SKIP SATISFY [isomitted($T+1)] MSG Work between holidays

       It's almost never appropriate to use MAYBE-UNCOMPUTABLE, but it is provided for those rare occasions when
       it  makes  sense.   If  you  use  MAYBE-UNCOMPUTABLE  inside  the evaltrig() function, then untriggerable
       triggers return -1.  For example:

               SET a evaltrig("MAYBE-UNCOMPUTABLE Mon SKIP OMIT Mon")

       will set a to -1.

DEBUGGING REMINDER SCRIPTS

       Although the command-line -d option is useful for debugging, it is often overkill.  For example,  if  you
       turn  on  the  -dx  option for a reminder file with many complex expressions, you'll get a huge amount of
       output.  The DEBUG command allows you to control the debugging flags under program control.   The  format
       is:

       DEBUG [+flagson] [-flagsoff]

       Flagson  and  flagsoff  consist  of  strings of the characters "extvlfs" that correspond to the debugging
       options discussed in the command-line options section.  If preceded with a "+", the  corresponding  group
       of  debugging options is switched on.  Otherwise, they are switched off.  For example, you could use this
       sequence to debug a complicated expression:

            DEBUG +x
            set a very_complex_expression(many_args)
            DEBUG -x

       THE DUMPVARS COMMAND

       The command DUMPVARS displays the values of variables in memory.  Its format is:

       DUMPVARS [var...]

       If you supply a space-separated list of variable names, the corresponding variables  are  displayed.   If
       you  do  not  supply  a  list of variables, then all variables in memory are displayed.  To dump a system
       variable, put its name in the list of variables to dump.  If you put a lone dollar sign in  the  list  of
       variables to dump, then all system variables will be dumped.

       THE ERRMSG COMMAND

       The ERRMSG command has the following format:

       ERRMSG body

       The body is passed through the substitution filter (with an implicit trigger date of today()) and printed
       to the error output stream.  Example:

            IF !defined("critical_var")
                 ERRMSG You must supply a value for "critical_var"
                 EXIT
            ENDIF

       THE EXIT COMMAND

       The above example also shows the use of the EXIT command.  This causes an unconditional exit from  script
       processing.   Any  queued  timed  reminders are discarded.  If you are in calendar mode (described next),
       then the calendar processing is aborted.

       If you supply an INT-type expression after the EXIT command, it is returned to the calling program as the
       exit status.  Otherwise, an exit status of 99 is returned.

       THE FLUSH COMMAND

       This  command  simply  consists  of the word FLUSH on a line by itself.  The command flushes the standard
       output and standard error streams used by Remind.  This is not terribly useful to most people, but may be
       useful if you run Remind as a subprocess of another program, and want to use pipes for communication.

CALENDAR MODE

       If  you  supply the -c, -s or -p command-line option, then Remind runs in "calendar mode."  In this mode,
       Remind interprets the script repeatedly, performing one iteration through the whole file for each day  in
       the  calendar.  Reminders that trigger are saved in internal buffers, and then inserted into the calendar
       in the appropriate places.

       If you also supply the -a option, then Remind will not include timed reminders in the calendar.

       The -p option is used in conjunction with the Rem2PS program to produce a calendar in PostScript  format.
       For example, the following command will send PostScript code to standard output:

            remind -p .reminders | rem2ps

       You can print a PostScript calendar by piping this to the lpr command.

       If you have a reminder script called ".reminders", and you execute this command:

            remind -c .reminders jan 1993

       then  Remind  executes  the  script  31  times,  once for each day in January.  Each time it executes the
       script, it increments the value of today().  Any reminders whose trigger date matches today() are entered
       into the calendar.

       MSG  and  CAL-type  reminders,  by  default, have their entire body inserted into the calendar.  RUN-type
       reminders are not normally inserted into the calendar.  However, if you enclose a portion of the body  in
       the %"...%" sequence, only that portion is inserted.  For example, consider the following:

            REM 6 Jan MSG %"Dianne's birthday%" is %b

       In  the  normal  mode,  Remind  would  print  "Dianne's birthday is today" on 6 January.  However, in the
       calendar mode, only the text "Dianne's birthday" is inserted into the box for 6 January.

       If you explicitly use the %"...%" sequence in a RUN-type reminder, then the text between  the  delimiters
       is  inserted  into  the  calendar.   If  you use the sequence %"%" in a MSG or CAL-type reminder, then no
       calendar entry is produced for that reminder.

       PRESERVING VARIABLES

       Because Remind iterates through the script for each day in the calendar,  slow  operations  may  severely
       reduce the speed of producing a calendar.

       For example, suppose you set the variables "me" and "hostname" as follows:

            SET me shell("whoami")
            SET hostname shell("hostname")

       Normally, Remind clears all variables between iterations in calendar mode.  However, if certain variables
       are slow to compute, and will not change between iterations, you can "preserve"  their  values  with  the
       PRESERVE  command.   Also, since function definitions are preserved between calendar iterations, there is
       no need to redefine them on each iteration.  Thus, you could use the following sequence:

            IF ! defined("initialized")
                 set initialized 1
                 set me shell("whoami")
                 set hostname shell("hostname")
                 fset func(x) complex_expr
                 preserve initialized me hostname
            ENDIF

       The operation is as follows:  On the first iteration through the script, "initialized"  is  not  defined.
       Thus,  the  commands  between IF and ENDIF are executed.  The PRESERVE command ensures that the values of
       initialized, me and hostname are preserved  for  subsequent  iterations.   On  the  next  iteration,  the
       commands  are  skipped,  since initialized has remained defined.  Thus, time-consuming operations that do
       not depend on the value of today() are done only once.

       Most system variables (those whose names start with '$') are  automatically  preserved  between  calendar
       iterations.

       Note  that  for  efficiency,  Remind  caches  the reminder script (and any INCLUDEd files) in memory when
       producing a calendar.

       Timed reminders are sorted and placed into the calendar in time order.  These are followed  by  non-timed
       reminders.   Remind  automatically places the time of timed reminders in the calendar according to the -b
       command-line option.  Reminders in calendar mode are sorted as if the -g option had been  used;  you  can
       change  the  sort  order  in calendar mode by explicitly using the -g option to specify a different order
       from the default.

       REPEATED EXECUTION

       If you supply a repeat parameter on the command line, and do not use the -c, -p, or  -s  options,  Remind
       operates  in a similar manner to calendar mode.  It repeatedly executes the reminder script, incrementing
       today() with each iteration.  The same rules about preserving variables and function  definitions  apply.
       Note  that using repeat on the command line also enables the -q option and disables any -z option.  As an
       example, if you want to see how Remind will behave for the next week, you can type:

            remind .reminders '*7'

       If you want to print the dates of the next 1000 days, use:

            (echo 'banner %'; echo 'msg [today()]%') | remind - '*1000'

INITIALIZING VARIABLES ON THE COMMAND LINE

       The -i option is used to initialize variables on the Remind command  line.   The  format  is  -ivar=expr,
       where expr is any valid expression.  Note that you may have to use quotes or escapes to prevent the shell
       from interpreting special characters in expr.  You can have as many -i options as you want on the command
       line,  and  they  are  processed  in  order.   Thus, if a variable is defined in one -i option, it can be
       referred to by subsequent -i options.

       Note that if you supply a date on the command line,  it  is  not  parsed  until  all  options  have  been
       processed.   Thus,  if  you  use  today()  in any of the -i expressions, it will return the same value as
       realtoday() and not the date supplied on the command line.

       Any variables defined on the command line are preserved as with the PRESERVE command.

       You should not have any spaces between the -i option and the  equal  sign;  otherwise,  strange  variable
       names are created that can only be accessed with the value() or defined() functions.

       You can also define a function on the command line by using:

       -ifunc(args)=definition

       Be sure to protect special characters from shell interpretation.

MORE ABOUT POSTSCRIPT

       The  PS  and  PSFILE reminders pass PostScript code directly to the printer.  They differ in that the PS-
       type reminder passes its body directly to the PostScript output (after  processing  by  the  substitution
       filter)  while  the PSFILE-type's body should simply consist of a filename.  The Rem2PS program will open
       the file named in the PSFILE-type reminder, and include its contents in the PostScript output.

       The PostScript-type reminders for a particular day are included in the PostScript output in sorted  order
       of  priority.   Note  that  the  order of PostScript commands has a major impact on the appearance of the
       calendars.  For example, PostScript code to shade a calendar box will obliterate  code  to  draw  a  moon
       symbol  if the moon symbol code is placed in the calendar first.  For this reason, you should not provide
       PS or PSFILE-type reminders with priorities; instead, you should ensure that they appear in the  reminder
       script  in  the  correct  order.   PostScript code should draw objects working from the background to the
       foreground, so that foreground objects  properly  overlay  background  ones.   If  you  prioritize  these
       reminders  and  run the script using descending sort order for priorities, the PostScript output will not
       work.

       All of the PostScript code for a particular date is enclosed in a save-restore pair.  However, if several
       PostScript-type reminders are triggered for a single day, each section of PostScript is not enclosed in a
       save-restore pair - instead, the entire body of included PostScript is enclosed.

       PostScript-type reminders are executed by the PostScript printer before  any  regular  calendar  entries.
       Thus,  regular calendar entries will overlay the PostScript-type reminders, allowing you to create shaded
       or graphical backgrounds for particular days.

       Before executing your PostScript code, the origin of the PostScript coordinate system  is  positioned  to
       the  bottom left-hand corner of the "box" in the calendar representing today().  This location is exactly
       in the middle of the intersection of the bottom and left black lines delineating the box - you  may  have
       to account for the thickness of these lines when calculating positions.

       Several  PostScript  variables  are  available  to the PostScript code you supply.  All distance and size
       variables are in PostScript units (1/72 inch.)  The variables are:

       LineWidth
              The width of the black grid lines making up the calendar.

       Border The border between the center of the grid lines and the space  used  to  print  calendar  entries.
              This border is normally blank space.

       BoxWidth and BoxHeight
              The width and height of the calendar box, from center-to-center of the black gridlines.

       InBoxHeight
              The  height  from the center of the bottom black gridline to the top of the regular calendar entry
              area.  The space from here to the top of the box is used only to draw the day number.

       /DayFont, /EntryFont, /SmallFont, /TitleFont and /HeadFont
              The fonts used to draw the day numbers, the calendar entries, the small  calendars,  the  calendar
              title (month, year) and the day-of-the-week headings, respectively.

       DaySize, EntrySize, TitleSize and HeadSize
              The  sizes  of  the  above fonts.  (The size of the small calendar font is not defined here.)  For
              example, if you wanted to print the Hebrew date next to the regular day number  in  the  calendar,
              use:

            REM PS Border BoxHeight Border sub DaySize sub moveto \
               /DayFont findfont DaySize scalefont setfont \
               ([hebday(today())] [hebmon(today())]) show

              Note how /DayFont and DaySize are used.

       Note that if you supply PostScript code, it is possible to produce invalid PostScript files.  Always test
       your PostScript thoroughly with a PostScript viewer before sending it to the printer.  You should not use
       any document structuring comments in your PostScript code.

DAEMON MODE

       If you use the -z command-line option, Remind runs in "daemon mode".  In this mode, no "normal" reminders
       are issued.  Instead, only timed reminders are collected and queued, and are then  issued  whenever  they
       reach their trigger time.

       In addition, Remind wakes up every few minutes to check the modification date on the reminder script (the
       filename supplied on the command line.)  If Remind detects that the script has  changed,  it  re-executes
       itself  in  daemon  mode,  and  interprets  the  changed script.  If Remind was compiled with support for
       inotify(7), then if the command-line reminder script is  really  a  directory,  Remind  also  re-executes
       itself if any of the files in the directory is changed.

       In daemon mode, Remind also re-reads the remind script when it detects that the system date has changed.

       In  daemon  mode,  Remind  acts  as  if  the  -f  option  had  been used, so to run in daemon mode in the
       background, use:

            remind -z .reminders &

       If you use sh or bash, you may have to use the "nohup" command to ensure that the daemon  is  not  killed
       when you log out.

PURGE MODE

       If  you  supply  the  -j command-line option, Remind runs in purge mode.  In this mode, it tries to purge
       expired reminders from your reminder files.

       In purge mode, Remind reads your reminder file and creates a new  file  by  appending  ".purged"  to  the
       original  file  name.   Note  that Remind never edits your original file; it always creates a new .purged
       file.

       If you invoke Remind against a directory instead of a file, then a .purged file is created for each *.rem
       file in the directory.

       Normally,  Remind  does  not  create  .purged files for INCLUDed files.  However, if you supply a numeric
       argument after -j, then Remind will create .purged  files  for  the  specified  level  of  INCLUDE.   For
       example,  if you invoke Remind with the argument -j2, then .purged files will be created for the file (or
       directory) specified on the command line, any files included by them, and any  files  included  by  those
       files.  However, .purged files will not be created for third-or-higher level INCLUDE files.

       Determining  which  reminders  have  expired  is  extremely tricky.  Remind does its best, but you should
       always compare the .purged file to the original file and hand-merge the changes back in.

       Remind annotates the .purged file as follows:

       An expired reminder is prefixed with:  #!P: Expired:

       In situations where Remind cannot reliably  determine  that  something  was  expired,  you  may  see  the
       following comments inserted before the problematic line:

          #!P: Cannot purge SATISFY-type reminders

          #!P: The next IF evaluated false...
          #!P: REM statements in IF block not checked for purging.

          #!P: The previous IF evaluated true.
          #!P: REM statements in ELSE block not checked for purging

          #!P: The next IFTRIG did not trigger.
          #!P: REM statements in IFTRIG block not checked for purging.

          #!P: Next line has expired, but contains expression...  please verify

          #!P: Next line may have expired, but contains non-constant expression

          #!P! Could not parse next line: Some-Error-Message-Here

       Remind  always annotates .purged files with lines beginning with "#!P".  If such lines are encountered in
       the original file, they are not copied to the .purged file.

SORTING REMINDERS

       The -g option causes Remind to sort reminders by trigger date, time and  priority  before  issuing  them.
       Note  that  reminders  are still calculated in the order encountered in the script.  However, rather than
       being issued immediately, they are saved in an internal buffer.  When Remind has finished processing  the
       script,  it  issues  the  saved  reminders  in sorted order.  The -g option can be followed by up to four
       characters that must all be "a" or "d".  The first character specifies the sort  order  by  trigger  date
       (ascending  or  descending),  the second specifies the sort order by trigger time and the third specifies
       the sort order by priority.  If the fourth character is "d", the  untimed  reminders  are  sorted  before
       timed  reminders.   The  default  is  to sort all fields in ascending order and to sort untimed reminders
       after timed reminders.

       In ascending order, reminders are issued with the most imminent first.  Descending order is the  reverse.
       Reminders  are always sorted by trigger date, and reminders with the same trigger date are then sorted by
       trigger time.  If two reminders have the same date and time, then the priority is  used  to  break  ties.
       Reminders with the same date, time and priority are issued in the order they were encountered.

       You  can  define  a  user-defined  function called SORTBANNER that takes one DATE-type argument.  In sort
       mode, the following sequence happens:

       If Remind notices that the next reminder to issue has a different trigger date from the previous one  (or
       if  it  is  the first one to be issued), then SORTBANNER is called with the trigger date as its argument.
       The result is coerced to a string, and passed  through  the  substitution  filter  with  the  appropriate
       trigger date.  The result is then displayed.

       Here's an example - consider the following fragment:

            # Switch off the normal banner
            BANNER %
            REM 11 March 1993 ++1 MSG Not so important
            REM 17 March 1993 ++7 MSG Way in the future
            REM 10 March 1993 MSG Important Reminder
            REM 11 March 1993 ++1 MSG Not so important - B
            FSET sortbanner(x) iif(x == today(), \
                 "***** THINGS TO DO TODAY *****", \
                 "----- Things to do %b -----")

       Running this with the -gaa option on 10 March 1993 produces the following output:

            ***** THINGS TO DO TODAY *****

            Important Reminder

            ----- Things to do tomorrow -----

            Not so important

            Not so important - B

            ----- Things to do in 7 days' time -----

            Way in the future

       You  can use the args() built-in function to determine whether or not SORTBANNER has been defined.  (This
       could be used, for example, to provide a default definition for SORTBANNER in a system-wide file included
       at the end of the user's file.)  Here's an example:

            # Create a default sortbanner function if it hasn't already
            # been defined
            if args("sortbanner") != 1
                 fset sortbanner(x) "--- Things to do %b ---"
            endif

MSGPREFIX() AND MSGSUFFIX()

       You  can define two functions in your script called msgprefix() and msgsuffix().  They should each accept
       one argument, a number from 0 to 9999.

       In normal mode, for MSG- and MSF-type reminders, the following sequence occurs  when  Remind  triggers  a
       reminder:

       o      If msgprefix() is defined, it is evaluated with the priority of the reminder as its argument.  The
              result is printed.  It is not passed through the substitution filter.

       o      The body of the reminder is printed.

       o      If msgsuffix() is defined, it is evaluated with the priority of the reminder as its argument.  The
              result is printed.  It is not passed through the substitution filter.

       Here's  an example:  The following definition causes priority-0 reminders to be preceded by "URGENT", and
       priority-6000 reminders to be preceded by "(not important)".

            fset msgprefix(x) iif(x==0, "URGENT: ", \
                 x==6000, "(not important) ", "")

       In Calendar Mode (with the -c, -s or -p options), an analogous pair of functions  named  calprefix()  and
       calsuffix()  can  be  defined.  They work with all reminders that produce an entry in the calendar (i.e.,
       CAL- and possibly RUN-type reminders as well as MSG-type reminders.)

       NOTES

       Normally, the body of a reminder is followed by a carriage return.  Thus, the results of msgsuffix() will
       appear  on  the  next line.  If you don't want this, end the body of the reminder with a percentage sign,
       "%".  If you want a space between your reminders, simply include a carriage return (char(13)) as part  of
       the msgsuffix() return value.

       If  Remind  has problems evaluating msgprefix(), msgsuffix() or sortbanner(), you will see a lot of error
       messages.  For an example of this, define the following:

            fset msgprefix(x) x/0

COMPILE-TIME SUPPORT FOR OTHER LANGUAGES

       Your version of Remind may have been compiled to support a language other than English.  This support may
       or  may not be complete - for example, all error and usage messages may still be in English.  However, at
       a minimum, non-English versions of Remind will output names  of  months  and  weekdays  in  the  selected
       language.  Also, the substitution mechanism will substitute constructs suitable for the selected language
       rather than for English.

       Note that a non-English version of Remind will accept only English names of  weekdays  and  months  in  a
       reminder script.

RUN-TIME SUPPORT FOR OTHER LANGUAGES

       Remind  has  run-time  support  for other languages, and it is expected that compile-time support will be
       deprecated in favour of run-time support.

       A number of system variables let  you  translate  various  phrases  to  other  languages.   These  system
       variables are:

       $Monday, $Tuesday, $Wednesday, $Thursday, $Friday, $Saturday, $Sunday
              Set  each  of these system variables to a string representing the corresponding day's name in your
              language.  Strings must be valid UTF-8 strings.

       $January, $February, $March, $April,  $May,  $June,  $July,  $August,  $September,  $October,  $November,
       $December
              Set each of these system variables to a string representing the corresponding month's name in your
              language.  Strings must be valid UTF-8 strings.

       $Ago, $Am, $And, $At, $Hour, $Is, $Minute, $Now, $On, $Pm, $Was
              Set each of these system variables to the translation of the corresponding English word into  your
              language.   Note  that  $Am  and  $Pm  should  be  the  translations of "AM" and "PM" (morning and
              afternoon time indicators) respectively.

       $Hplu, $Mplu
              Set these to the suffix to add to the word for "hour"  and  "minute"  to  make  them  plural.   In
              English, both would be set to "s".

       $Fromnow
              Set this to the translation of the English phrase "from now"

       Note  that  if  you  set any of the language-related system variables, they should be set in a section of
       your script that always is evaluated.  If you set them inside an IF statement, for example,  results  are
       unpredictable.

       Note  also  that  the Rem2PS back-end does not support the full range of UTF-8 characters.  The TkRemind,
       rem2html and rem2pdf back-ends all do support the full UTF-8 range.

RUN-TIME MODIFICATION OF THE SUBSTITUTION FILTER

       The system variables mentioned in the previous section are not typically sufficient to properly translate
       Remind's output to another language.  Some languages have complicated rules for AM vs PM times and others
       have complex rules for making words plural.  Remind therefore allows you to define a number of  functions
       that modify the behavior of the substitution filter at run-time.  The functions are:

       subst_ampm(h)
              This  function is passed a single integer, namely an hour from 0 to 23.  It should return a string
              that indicates "AM" or "PM" or even finer gradations in some languages.

       subst_ordinal(d)
              This function is passed a single integer, namely a day of the month  from  1  to  31.   It  should
              return a string that is suffixed to the day number to turn it into an ordinal number.  In English,
              for example, the function might return "st", "nd", "rd" or "th", depending on d.

       subst_N(alt, date, time)
              This is actually a family of functions, where N is a letter or number.  This  function  completely
              overrides  the  substitution sequence "%N".  The three arguments are an integer alt which, if non-
              zero, indicates that the alternate-mode substitution sequence "%*N" was encountered; date which is
              the trigger date of the reminder and time which is the trigger time.

       subst_Nx(alt, date, time)
              Again,  this  is  a  family  of  functions.  It is similar to the subst_N family except it is only
              called if date is two or more days away from today().   This  is  useful  if  you  don't  want  to
              override the "today" or "tomorrow" output for most substitution sequences.

       Here's  an  example  of how you might customize your substitution filter.  Suppose you want to change the
       "%b" sequence to substitute "the day after tomorrow" for an event two days from now.  You could do this:

           FSET subst_bx(a,d,t) iif(d==today()+2, "the day after tomorrow", \
                                    "in " + (d-today()) + " days' time")
           REM [today()+3] ++3 MSG Event 1 is %b%
           REM [today()+2] ++3 MSG Event 2 is %b%
           REM [today()+1] ++3 MSG Event 3 is %b%
           REM [today()]   ++3 MSG Event 4 is %b%

       The output of this script is:

           Event 1 is in 3 days' time
           Event 2 is the day after tomorrow
           Event 3 is tomorrow
           Event 4 is today

       Note how Event 2's wording was changed from the normal  "in  2  days'  time",  and  note  also  that  the
       "tomorrow"  and  "today" events used the normal substitution---subst_bx is not called for trigger days of
       today or tomorrow.

       As a special case, if a  subst_Nx  or  subst_N  function  returns  the  integer  zero,  then  the  normal
       substitution mechanism is used.  Therefore, the previous example could have been written more simply as:

           FSET subst_bx(a,d,t) iif(d==today()+2, "the day after tomorrow", 0)

       You  can  define  your  own  substitution  sequences in addition to the built-in ones as follows:  If you
       define a function named subst_name(alt, date, time), then the sequence %{name} calls  the  function  with
       alt  set  to  0  and  date  and time to the trigger date and time, respectively.  The %{name} sequence is
       replaced with whatever the function returns.  The sequence %*{name} is similar, but  calls  the  function
       with alt set to 1.

       If  you  use  a  %{name}  sequence  and  the function subst_name is not defined or returns an error, then
       %{name} is replaced with the empty string.

LANGUAGE PACKS

       Remind  ships  with  a  number  of  language  packs,  which  are  simply  reminder  scripts  located   in
       [$SysInclude]/lang.  The currently-shipping language packs are:

       da.rem  (Danish),  de.rem  (German),  es.rem  (Spanish),  fr.rem  (French),  is.rem  (Icelandic),  it.rem
       (Italian),  nl.rem  (Dutch),  no.rem  (Norwegian),  pl.rem  (Polish),  pt.rem  (Portuguese)  and   ro.rem
       (Romanian).

       To use a language pack (in this example, de.rem), simply place this at the top of your reminders file:

           INCLUDE [$SysInclude]/lang/de.rem

       If you want Remind to try to find the language pack appropriate for your locale settings, use:

           INCLUDE [$SysInclude]/lang/auto.rem

       You are encouraged to study the language packs to see how to translate Remind into additional languages.

THE HEBREW CALENDAR

       Remind  has  support  for the Hebrew calendar, which is a luni-solar calendar.  This allows you to create
       reminders for Jewish holidays, jahrzeits (anniversaries of deaths) and smachot (joyous occasions.)

       THE HEBREW YEAR

       The Hebrew year has 12 months, alternately 30 and 29  days  long.   The  months  are:  Tishrey,  Heshvan,
       Kislev,  Tevet, Shvat, Adar, Nisan, Iyar, Sivan, Tamuz, Av and Elul.  In Biblical times, the year started
       in Nisan, but Rosh Hashana (Jewish New Year) is now celebrated on the 1st and 2nd of Tishrey.

       In a cycle of 19 years, there are 7 leap years, being years 3, 6, 8, 11, 14, 17 and 19 of the cycle.   In
       a leap year, an extra month of 30 days is added before Adar.  The two Adars are called Adar A and Adar B.

       For  certain  religious  reasons,  the year cannot start on a Sunday, Wednesday or Friday.  To adjust for
       this, a day is taken off Kislev or added to Heshvan.  Thus, a regular year can have from 353 to 355 days,
       and a leap year from 383 to 385.

       When  Kislev or Heshvan is short, it is called chaser, or lacking.  When it is long, it is called shalem,
       or full.

       The Jewish date changes at sunset.  However, Remind will change the date at midnight, not sunset.  So  in
       the  period  between  sunset  and midnight, Remind will be a day earlier than the true Jewish date.  This
       should not be much of a problem in practice.

       The computations for the Jewish calendar were based on the program "hdate" written by Amos Shapir of  the
       Hebrew University of Jerusalem, Israel.  He also supplied the preceding explanation of the calendar.

       HEBREW DATE FUNCTIONS

       hebday(d_date)
              Returns  the  day  of the Hebrew month corresponding to the date parameter.  For example, 12 April
              1993 corresponds to 21 Nisan 5753.  Thus, hebday('1993/04/12') returns 21.

       hebmon(d_date)
              Returns the name of the Hebrew month corresponding to  date.   For  example,  hebmon('1993/04/12')
              returns "Nisan".

       hebyear(d_date)
              Returns the Hebrew year corresponding to date.  For example, hebyear('1993/04/12') returns 5753.

       hebdate(i_day, s_hebmon [,id_yrstart [,i_jahr [,i_aflag]]])
              The hebdate() function is the most complex of the Hebrew support functions.  It can take from 2 to
              5 arguments.  It returns a DATE corresponding to the Hebrew date.

              The day parameter can range from 1 to 30, and specifies the day of the Hebrew month.   The  hebmon
              parameter  is  a  string  that  must name one of the Hebrew months specified above.  Note that the
              month must be spelled out in full, and use the English transliteration shown previously.  You  can
              also specify "Adar A" and "Adar B."  Month names are not case-sensitive.

              The  yrstart  parameter can either be a DATE or an INT.  If it is a DATE, then the hebdate() scans
              for the first Hebrew date on or after that date.  For example:

                        hebdate(15, "Nisan", '1990/01/01')

              returns 1990/03/30, because that is the first occurrence of 15 Nisan on or after 1 January 1990.

              If yrstart is an INT, it is interpreted as a Hebrew year.  Thus:

                        hebdate(22, "Kislev", 5756)

              returns 1995/12/15, because that date corresponds to 22 Kislev,  5756.   Note  that  none  of  the
              Hebrew date functions will work with dates outside Remind's normal range for dates.

              If yrstart is not supplied, it defaults to today().

              The jahr modifies the behaviour of hebdate() as follows:

              If  jahr  is  0  (the  default),  then hebdate() keeps scanning until it finds a date that exactly
              satisfies the other parameters.  For example:

                        hebdate(30, "Adar A", 1993/01/01)

              returns 1995/03/02, corresponding to 30 Adar A, 5755, because that is the next  occurrence  of  30
              Adar  A  after 1 January, 1993.  This behaviour is appropriate for Purim Katan, which only appears
              in leap years.

              If jahr is 1, then the date is modified as follows:

              o      30 Heshvan is converted to 1 Kislev in years when Heshvan is chaser

              o      30 Kislev is converted to 1 Tevet in years when Kislev is chaser

              o      30 Adar A is converted to 1 Nisan in non-leapyears

              o      Other dates in Adar A are moved to the corresponding day in Adar in non-leapyears

              This behaviour is appropriate for  smachot  (joyous  occasions)  and  for  some  jahrzeits  -  see
              "JAHRZEITS."

              if jahr is 2, then the date is modified as follows:

              o      30  Kislev  and  30 Heshvan are converted to 29 Kislev and 29 Heshvan, respectively, if the
                     month is chaser

              o      30 Adar A is converted to 30 Shvat in non-leapyears

              o      Other dates in Adar A are moved to the corresponding day in Adar in non-leapyears

              if jahr is not 0, 1, or 2, it is interpreted as a Hebrew year, and the behaviour is calculated  as
              described in the next section, "JAHRZEITS."

              The  aflag  parameter  modifies the behaviour of the function for dates in Adar during leap years.
              The aflag is only used if yrstart is a DATE type.

              The aflag only affects date calculations if hebmon is specified as "Adar".   In  leap  years,  the
              following algorithm is followed:

              o      If aflag is 0, then the date is triggered in Adar B.  This is the default.

              o      If aflag is 1, then the date is triggered in Adar A.  This may be appropriate for jahrzeits
                     in the Ashkenazi tradition; consult a rabbi.

              o      If aflag is 2, then the date is triggered in both Adar A and Adar B of a leap  year.   Some
                     Ashkenazim perform jahrzeit in both Adar A and Adar B.

       JAHRZEITS

       A  jahrzeit  is a yearly commemoration of someone's death.  It normally takes place on the anniversary of
       the death, but may be delayed if burial is delayed - consult a rabbi for more information.

       In addition, because some months change length, it is not obvious which day the anniversary  of  a  death
       is.  The following rules are used:

       o      If  the  death occurred on 30 Heshvan, and Heshvan in the year after the death is chaser, then the
              jahrzeit is observed on 29 Heshvan in years when Heshvan is chaser.  Otherwise,  the  jahrzeit  is
              observed on 1 Kislev when Heshvan is chaser.

       o      If  the  death  occurred  on 30 Kislev, and Kislev in the year after the death is chaser, then the
              jahrzeit is observed on 29 Kislev in years when Kislev is  chaser.   Otherwise,  the  jahrzeit  is
              observed on 1 Tevet when Kislev is chaser.

       o      If the death occurred on 1-29 Adar A, it is observed on 1-29 Adar in non-leapyears.

       o      If the death occurred on 30 Adar A, it is observed on 30 Shvat in a non-leapyear.

       Specifying  a  Hebrew year for the jahr parameter causes the correct behaviour to be selected for a death
       in that year.  You may also have to specify aflag, depending on your tradition.

       The jahrzeit information was supplied by Frank Yellin, who quoted "The Comprehensive Hebrew Calendar"  by
       Arthur Spier, and "Calendrical Calculations" by E. M. Reingold and Nachum Dershowitz.

OUT-OF-BAND REMINDERS

       The SPECIAL keyword is used to transmit "out-of-band" information to Remind backends, such as tkremind or
       Rem2PS.  They are used only when piping data from a remind -p line.  (Note that the COLOR special  is  an
       exception; it downgrades to the equivalent of MSG in Remind's normal mode of operation.)

       The  various  SPECIALs  recognized are particular for each backend; however, there are four SPECIALs that
       all backends should attempt to support.  They are currently supported by Rem2PS, tkremind and rem2html.

       The SHADE special replaces the psshade() function.  Use it like this:

            REM Sat Sun SPECIAL SHADE 128
            REM Mon SPECIAL SHADE 255 0 0

       The SHADE keyword is followed by either one or three numbers, from 0 to 255.  If one number is  supplied,
       it  is  interpreted  as a grey-scale value from black (0) to white (255).  If three numbers are supplied,
       they are interpreted as RGB components from minimum (0) to  maximum  (255).   The  example  above  shades
       weekends a fairly dark grey and makes Mondays a fully-saturated red.  (These shadings appear in calendars
       produced by Rem2PS, tkremind and rem2html.)

       The MOON special replaces the psmoon() function.  Use it like this:

            REM [moondate(0)] SPECIAL MOON 0
            REM [moondate(1)] SPECIAL MOON 1
            REM [moondate(2)] SPECIAL MOON 2
            REM [moondate(3)] SPECIAL MOON 3

       These draw little moons on the various calendars.  The complete syntax of the MOON special is as follows:

            ... SPECIAL MOON phase moonsize fontsize msg

       Phase is a number from 0 to 3, with 0 representing a new moon, 1 the first quarter, 2 a full moon  and  3
       the last quarter.

       moonsize  is  the  diameter  in  PostScript units of the moon to draw.  If omitted or supplied as -1, the
       backend chooses an appropriate size.

       fontsize is the font size in PostScript units of the msg

       Msg is additional text that is placed near the moon glyph.

       Note that only the Rem2PS backend supports moonsize and fontsize; the other backends use fixed sizes.

       The COLOR special lets you place colored reminders in the calendar.  Use it like this:

            REM ... SPECIAL COLOR 255 0 0 This is a bright red reminder
            REM ... SPECIAL COLOR 0 128 0 This is a dark green reminder

       You can spell COLOR either the American way ("COLOR") or the British way ("COLOUR").   This  manual  will
       use the American way.

       Immediately  following  COLOR should be three decimal numbers ranging from 0 to 255 specifying red, green
       and blue intensities, respectively.  The rest of the line is the text to put in the calendar.

       The COLOR special is "doubly special", because in its  normal  operating  mode,  remind  treats  a  COLOR
       special  just  like  a  MSG-type  reminder.   Also, if you invoke Remind with -@[n], then it approximates
       SPECIAL COLOR reminders on your terminal.

       See also the documentation of the $DefaultColor system variable in the section "SYSTEM VARIABLES".

       The WEEK special lets you place annotations such as the week number in the calendar.  For  example,  this
       would  number  each  Monday with the ISO 8601 week number.  The week number is shown like this: "(Wn)" in
       this example, but you can put whatever text you like after the WEEK keyword.

            REM Monday SPECIAL WEEK (W[weekno()])

MISCELLANEOUS

       COMMAND AND KEYWORD ABBREVIATIONS

       The following tokens can be abbreviated:

       o      REM can be omitted - it is implied if no other valid command is present.

       o      CLEAR-OMIT-CONTEXT --> CLEAR

       o      PUSH-OMIT-CONTEXT --> PUSH

       o      POP-OMIT-CONTEXT --> POP

       o      DUMPVARS --> DUMP

       o      BANNER --> BAN

       o      INCLUDE --> INC

       o      MAYBE-UNCOMPUTABLE --> MAYBE

       o      SCANFROM --> SCAN

       NIFTY EXAMPLES

       This section is a sampling of what you can do with Remind.

            REM 5 Feb 1991 AT 14:00 +45 *30 \
            RUN mail -s "Meeting at %2" $LOGNAME </dev/null &

       On 5 February, 1991, this reminder will mail you reminders of a 2:00pm meeting at 1:15,  1:45  and  2:00.
       The subject of the mail message will be "Meeting at 2:00pm" and the body of the message will be blank.

            REM AT 17:00 RUN echo "5:00pm - GO HOME!" | xless -g +0+0 &

       This  reminder  will  pop up an xless window at 5:00pm every day.  The xless window will contain the line
       "5:00pm - GO HOME!"

            REM AT 23:59 RUN (sleep 120; remind -a [filename()]) &

       This reminder will run at one minute to midnight.  It will cause a new Remind process  to  start  at  one
       minute  past midnight.  This allows you to have a continuous reminder service so you can work through the
       night and still get timed reminders for early in  the  morning.   Note  that  this  trick  is  no  longer
       necessary, providing you run Remind in daemon mode.

            remind -c12 /dev/null Jan 1993

       This invocation of Remind will cause it to print a calendar for 1993, with all entries left blank.

            REM CAL [trigdate()-date(year(trigdate()), 1, 1)+1]

       This  example puts an entry in each box of a calendar showing the number (1-365 or 366) of the day of the
       year.

            REM Tue 2 Nov SATISFY (year(trigdate())%4) == 0
            IF trigvalid()
                 REM [trigdate()] ++5 MSG \
                 U.S. Presidential Election!!
            ENDIF

       This example warns you 5 days ahead of each  American  presidential  election.   The  first  REM  command
       calculates  the  first  Tuesday  after  the  first  Monday in November.  (This is equivalent to the first
       Tuesday on or after 2 November.)  The SATISFY clause ensures that the trigger  date  is  issued  only  in
       election years, which are multiples of 4.  The second REM command actually issues the reminder.

       DETAILS ABOUT TRIGGER COMPUTATION

       Here  is  a conceptual description of how triggers are calculated.  Note that Remind actually uses a much
       more efficient procedure, but the results are the same as if the conceptual procedure had been followed.

       Remind starts from the current date (that is, the value of today()) and scans forward, examining each day
       one  at  a  time until it finds a date that satisfies the trigger, or can prove that no such dates (on or
       later than today()) exist.

       If Remind is executing a SATISFY-type reminder, it evaluates the expression with trigdate()  set  to  the
       date  found above.  If the expression evaluates to zero or the null string, Remind continues the scanning
       procedure described above, starting with the day after the trigger found above.

       The SCANFROM clause (having a syntax similar to UNTIL) can modify the  search  strategy  used.   In  this
       case,  Remind  begins  the  scanning  procedure at scan_date, which is the date specified in the SCANFROM
       clause.  For example:

            REM Mon 1 SCANFROM 17 Jan 1992 MSG Foo

       The example above will always have a trigger date of Monday, 3 February 1992.   That  is  because  Remind
       starts  scanning  from  17 January 1992, and stops scanning as soon as it hits a date that satisfies "Mon
       1."

       The main use of SCANFROM is in situations where you want to calculate the positions of floating holidays.
       Consider the Labour Day example shown much earlier.  Labour Day is the first Monday in September.  It can
       move over a range of 7 days.  Consider the following sequence:

            REM Mon 1 Sept SCANFROM [today()-7] ADDOMIT MSG Labour Day
            REM Mon AFTER MSG Hello

       The SCANFROM clause makes sure that Remind begins scanning from 7 days before  the  current  date.   This
       ensures  that  Labour  Day  for  the current year will continue to be triggered until 7 days after it has
       occurred.  This allows you to safely use the AFTER keyword as shown.

       As a special case, you can simply use  a  negative  number  after  SCANFROM;  a  negative  number  -N  is
       interpreted as N days before today.  Thus, the previous example could also be written like this:

            REM Mon 1 Sept SCANFROM -7 ADDOMIT MSG Labour Day
            REM Mon AFTER MSG Hello

       In  general, use SCANFROM as shown for safe movable OMITs.  The amount you should scan back by (7 days in
       the example above) depends on the number of possible consecutive OMITted days that may occur, and on  the
       range of the movable holiday.  Generally, a value of 7 is safe.

       The FROM clause operates almost like the counterpoint to UNTIL.  It prevents the reminder from triggering
       before the FROM date.  For example, the following reminder:

            REM Mon Thu FROM 23 Jul 2007 UNTIL 2 Aug 2007 MSG Test

       will trigger on Mondays and Thursdays between 23 July 2007 and 2 August 2007 inclusive.

       FROM is really just syntactic sugar; you could implement the reminder above as follows:

            REM Mon Thu SCANFROM [max(today(), '2007-07-23')] \
                   UNTIL 2 Aug 2007 MSG Test

       but that's a lot harder to read.  Internally, Remind treats FROM exactly as illustrated  using  SCANFROM.
       For that reason, you cannot use both FROM and SCANFROM.

       Note  that if you use one REM command to calculate a trigger date, perform date calculations (addition or
       subtraction, for example) and then use the modified date in a subsequent REM command, the results may not
       be  what  you intended.  This is because you have circumvented the normal scanning mechanism.  You should
       try to write REM commands that compute trigger dates that  can  be  used  unmodified  in  subsequent  REM
       commands.  The file "defs.rem" that comes with the Remind distribution contains examples.

       DETAILS ABOUT TRIGVALID()

       The  trigvalid()  function  returns  1 if Remind could find a trigger date for the previous REM or IFTRIG
       command.  More specifically, it returns 1 if Remind finds a date not before  the  starting  date  of  the
       scanning that satisfies the trigger.  In addition, there is one special case in which trigvalid() returns
       1 and trigdate() returns a meaningful result:

       If the REM or IFTRIG command did not contain an UNTIL clause, and contained all of  the  day,  month  and
       year  components,  then Remind will correctly compute a trigger date, even if it happens to be before the
       start of scanning.  Note that this behaviour is not true for versions of Remind prior to 03.00.01.

FILES

       The traditional location of your reminders file or directory is:

               $HOME/.reminders

       where $HOME is your home directory.

       Remind ships with some preinstalled files for holidays and language packs.   These  are  located  in  the
       following directory:

               /usr/share/remind/

       Do  not  hard-code the above directory in your reminder files.  Instead, use the value of the $SysInclude
       system variable.

AUTHOR

       Dianne Skoll <dianne@skoll.ca> wrote Remind.  The moon code was copied largely unmodified from "moontool"
       by John Walker.  The sunrise and sunset functions use ideas from programs by Michael Schwartz and Marc T.
       Kaufman.  The Hebrew calendar support was taken from "hdate" by Amos Shapir.  OS/2 support  was  done  by
       Darrel  Hankerson,  Russ  Herman,  and  Norman  Walsh.  The supported languages and their translators are
       listed below.  Languages marked  "complete"  support  error  messages  and  usage  instructions  in  that
       language; all others only support the substitution filter mechanism and month/day names.

       German -- Wolfgang Thronicke

       Dutch -- Willem Kasdorp and Erik-Jan Vens

       Finnish -- Mikko Silvonen (complete)

       French -- Laurent Duperval (complete)

       Norwegian -- Trygve Randen

       Danish -- Mogens Lynnerup

       Polish -- Jerzy Sobczyk (complete)

       Brazilian Portuguese -- Marco Paganini (complete)

       Italian -- Valerio Aimale

       Romanian -- Liviu Daia

       Spanish -- Rafa Couto

       Icelandic -- Björn Davíðsson

BUGS

       If you find a bug in Remind, please report it to: dianne@skoll.ca

       There's  no good reason why read-only system variables are not implemented as functions, or why functions
       like version(), etc.  are not implemented as read-only system variables.

       Hebrew dates in Remind change at midnight instead of sunset.

       Remind has some built-in limits (for example, number of global OMITs.)

BIBLIOGRAPHY

       Nachum Dershowitz and Edward M. Reingold, "Calendrical Calculations", Software-Practice  and  Experience,
       Vol. 20(9), Sept. 1990, pp 899-928.

       L. E. Doggett, Almanac for computers for the year 1978, Nautical Almanac Office, USNO.

       Richard Siegel and Michael and Sharon Strassfeld, The First Jewish Catalog, Jewish Publication Society of
       America.

       Jean Meeus, Astronomical Algorithms, Second Edition, Willmann-Bell, Inc.

HOME PAGE

       https://dianne.skoll.ca/projects/remind/

MAILING LIST

       https://dianne.skoll.ca/mailman/listinfo/remind-fans

SEE ALSO

       rem(1), rem2ps(1), rem2pdf(1), tkremind(1), rem2html(1)