NAME

       parsedate - convert time and date string to number

SYNOPSIS

       #include <sys/types.h>

       typedef struct _TIMEINFO {
           time_t           time;
           long             usec;
           long             tzone;
       } TIMEINFO;

       time_t
       parsedate(text, now)
           char             *text;
           TIMEINFO         *now;

DESCRIPTION

       Parsedate  converts  many common time specifications into the number of seconds since the epoch — i.e., a
       time_t; see time(2).

       Parsedate returns the time, or -1 on error.  Text is a character string containing  the  time  and  date.
       Now  is  a  pointer to the time that should be used for calculating relative dates.  If now is NULL, then
       GetTimeInfo in libinn(3) is used to obtain the current time and timezone.

       The character string consists of zero or more specifications of the following form:

       time   A time of day, which is of the form hh[:mm[:ss]] [meridian] [zone] or hhmm [meridian] [zone].   If
              no meridian is specified, hh is interpreted on a 24-hour clock.

       date   A  specific  month and day with optional year.  The acceptable formats are mm/dd[/yy], yyyy/mm/dd,
              monthname dd[, yy], dd monthname [yy], and day, dd monthname yy.  The default year is the  current
              year.  If the year is less then 100, then 1900 is added to it; if it is less then 21, then 2000 is
              added to it.

       relative time
              A specification relative to the current time.  The format is number  unit;  acceptable  units  are
              year,  month, week, day, hour, minute (or min), and second (or sec).  The unit can be specified as
              a singular or plural, as in 3 weeks.

       The actual date is calculated according to the following steps.  First, any absolute date and/or time  is
       processed  and  converted.   Using  that  time  as the base, day-of-week specifications are added.  Next,
       relative specifications are used.  If a date or day is specified, and no absolute  or  relative  time  is
       given,  midnight  is  used.   Finally,  a  correction  is  applied so that the correct hour of the day is
       produced after allowing for daylight savings time differences.

       Parsedate ignores case when parsing all words; unknown words are taken to be unknown timezones, which are
       treated  as  GMT.   The  names of the months and days of the week can be abbreviated to their first three
       letters, with optional trailing period.  Periods are ignored in any timezone or meridian values.

BUGS

       Parsedate does not accept all desirable and unambiguous constructions.  Semantically incorrect dates such
       as ``February 31'' are accepted.

       Daylight  savings time is always taken as a one-hour change which is wrong for some places.  The daylight
       savings time correction can get confused if parsing a time within an hour of when the reckoning  changes,
       or if given a partial date.

HISTORY

       Originally written by Steven M. Bellovin <smb@research.att.com> while at the University of North Carolina
       at Chapel Hill and distributed under the name getdate.

       A major overhaul was done by Rich $alz <rsalz@bbn.com> and Jim Berets <jberets@bbn.com> in August, 1990.

       It was further revised (primarily to remove obsolete constructs and timezone names) a year later by  Rich
       (now  <rsalz@osf.org>)  for  InterNetNews,  and  the  name  was  changed.   This  is revision 1.10, dated
       1993/01/29.

SEE ALSO

       date(1), ctime(3), libinn(3), time(2).

                                                                                                    PARSEDATE(3)