Provided by: faketime_0.8-1_amd64 bug


       faketime - manipulate the system time for a given command


       faketime [options] timestamp program [arguments...]


       The  given  command will be tricked into believing that the current system time is the one
       specified in the timestamp. The wall clock will continue to run from this  date  and  time
       unless  specified otherwise (see advanced options). Actually, faketime is a simple wrapper
       for libfaketime, which uses the  LD_PRELOAD  mechanism  to  load  a  small  library  which
       intercepts  system  calls  to functions such as time(2) and fstat(2). This wrapper exposes
       only a subset of libfaketime's functionality; please refer to the README  file  that  came
       with faketime for more details and advanced options.


       --help show usage information and quit.

              show version information and quit.

       -m     use the multi-threading variant of libfaketime.

       -f     use the advanced timestamp specification format.


       faketime 'last Friday 5 pm' /bin/date
       faketime '2008-12-24 08:15:42' /bin/date
       faketime -f '+2,5y x10,0' /bin/bash -c 'date; while true; do echo $SECONDS ; sleep 1 ; done'
       faketime -f '+2,5y x0,50' /bin/bash -c 'date; while true; do echo $SECONDS ; sleep 1 ; done'
       (Please note that it depends on your locale settings whether . or , has to be used for fractional offsets)


       The  simple  timestamp  format  used  by default applies the /bin/date -d command to parse
       user-friendly specifications such as 'last friday'. When using the faketime option -f, the
       timestamp specified on the command line is directly passed to libfaketime, which enables a
       couple of additional features such as speeding the clock up or slowing  it  down  for  the
       target  program.  It  is strongly recommended that you have a look at the README file that
       came with faketime for the details. Summary:

       Freeze clock at absolute timestamp: "YYYY-MM-DD hh:mm:ss"
              If you want to specify an absolute point in time, exactly this format must be used.
              Please  note that freezing the clock is usually not what you want and may break the
              application. Only use if you know what you're doing!

       Relative time offset: "[+/-]123[m/h/d/y], e.g. "+60m", "+2y"
              This is the most often used format and specifies the faked time relatively  to  the
              current real time. The first character of the format string must be a + or a -. The
              numeric value by default represents seconds, but the modifiers m, h, d, and  y  can
              be used to specify minutes, hours, days, or years, respectively. For example, "-2y"
              means "two years ago". Fractional time offsets can be  used,  e.g.  "+2,5y",  which
              means "two and a half years in the future". Please note that the fraction delimiter
              depends on your locale settings, so if "+2,5y" does not work, you might want to try

       Start-at timestamps: "@YYYY-MM-DD hh:mm:ss"
              The wall clock will start counting at the given timestamp for the program. This can
              be used for specifying absolute timestamps without freezing the clock.


       When using relative time offsets or start-at timestamps  (see  ADVANCED  TIMESTAMP  FORMAT
       above  and option -f), the clock speed can be adjusted, i.e. time may run faster or slower
       for the executed program. For example, "+5y x10" will set the faked time 5 years into  the
       future and make the time pass 10 times as fast (one real second equals 10 seconds measured
       by the program). Similarly, the flow of time can be slowed, e.g. using "-7d  x0,2",  which
       will  set the faked time 7 days in the past and set the clock speed to 20 percent, i.e. it
       takes five real world seconds for one second measured by the program. Again, depending  on
       your locale, either "x2.0" or "x2,0" may be required regarding the delimiter.

       Faking  times  for  multiple  programs  or  even  system-wide  can  be simplified by using
       ~/.faketimerc files and /etc/faketimerc.  Please  refer  to  the  README  that  came  with
       faketime for warnings and details.


       Maintained by Wolfgang Hommel <>. Please see the README and Changelog
       files for contributers.


       Due to limitations of the LD_PRELOAD mechanism, faketime will not work with  suidroot  and
       statically  linked  programs.   While  timestamps  and  time  offsets  will work for child
       processes, speeding the clock up or slowing it down might not  work  for  child  processes
       spawned  by  the  executed  program as expected; a new instance of libfaketime is used for
       each child process, which means that the libfaketime start time, which is  used  in  speed
       adjustments, will also be re-initialized.


       Please send an e-mail to Wolfgang Hommel <>


       Copyright © 2003-2008 by Wolfgang Hommel.

       There  is  NO  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
       You may redistribute copies of faketime under the terms of the GNU General Public License.
       For more information about these matters, see the file named COPYING.

SEE ALSO, time(2), fstat(2)