DATE(1)                     386BSD Reference Manual                    DATE(1)

NAME
     date - Display or set date and time

SYNOPSIS
     date [-d dst] [-r seconds] [-t minutes_west] [-nu] [+format]
          [[[[[[CC]YY]MM]DD]HH]MM[.ss]]

DESCRIPTION
     Date displays the current date and time when invoked without arguments.
     Providing arguments will format the date and time in a user-defined way
     or set the date.  Only the superuser may set the date.

     The options are as follows:

     -d      Set the kernel's values for daylight savings time.  If dst is
             non-zero, future calls to gettimeofday(2) will return a non-zero
             `tz_dsttime'.

     -n      The utility timed(8) is used to synchronize the clocks of groups
             of machines.  By default, if timed is running, date will set the
             time on all of the machines in the local group.  The -n option
             stops date from setting the time for other than the current
             machine.

     -r      Print out the date and time for seconds from the Epoch.

     -t      Set the kernel's values for minutes west of GMT. Minutes_west
             specifies the number of minutes returned in `tz_minuteswest' by
             future calls to gettimeofday(2).

     -u      Display or set the date in UCT (universal) time.

     An operand with a leading plus (``+'') sign signals a user-defined format
     string which specifies the format in which to display the date and time.
     The format string may contain any of the conversion specifications
     described in the strftime(3) manual page, as well as any arbitrary text.
     The format string for the default display is:

           ``%a %b %e %H:%M:%S %Z %Y%n''.

     If an operand does not have a leading plus sign, it is interpreted as a
     value for setting the system's notion of the current date and time.  The
     canonical representation for setting the date and time:

           cc      Century in abbreviated form (.e.g 19 for 1989).
           yy      Year in abbreviated form (.e.g 89 for 1989).
           mm      Numeric month.  A number from 1 to 12.
           dd      Day, a number from 1 to 31.
           hh      Hour, a number from 0 to 23.
           mm      Minutes, a number from 0 to 59.
           .ss     Seconds, a number from 0 to 59.

     Everything but the minutes are optional.

     Time changes for Daylight Saving and Standard time and leap seconds and
     years are handled automatically.

EXAMPLES
     The command:

           date ``+DATE: %m/%d/%y%nTIME: %H:%M:%n''


     will display:

           DATE: 11/21/87
           TIME: 13:36:16

     The command:

           date 8506131627

     sets the date to ``June 13 1985, 4:27 PM''.

     The command:

           date 1432

     sets the time to 2:32 PM, without modifying the date.

FILES
     /var/log/wtmp      A record of date resets and time changes.
     /var/log/messages  A record of the user setting the time.

SEE ALSO
     gettimeofday(2),  strftime(3),  utmp(5),  timed(8)

     R. Gusella, and S. Zatti, TSP: The Time Synchronization Protocol for UNIX
     4.3BSD.

DIAGNOSTICS
     Exit status is 0 on success, 1 if unable to set the date, and 2 if able
     to set the local date but failing to set it globally.

     Occasionally, when timed synchronizes the time on many hosts, the setting
     of a new time value may require more than a few seconds.  On these
     occasions, date prints: `Network time being set'. The message
     `Communication error with timed' occurs when the communication between
     date and timed fails.

BUGS
     386BSD internally uses an absolute form of universal time, which is
     converted back into local time when displayed. Since the computers
     hardware clock records local time, and it is used to derive the initial
     time at boot, it is imperitive that the rules for converting local time
     be correctly configured for time to be properly set by the system. Also,
     any drift in either the battery-powered real time clock (N.B. some of
     these radically increase in speed as the battery dies), or the
     rescheduling clock (in cheap clones, sometimes they don't even have
     crystal clocks!) may result in inaccurate time. Use of network time and
     the timed(8) daemon may provide a more reliable source of time.

HISTORY
     The date command is expected to be compatible with IEEE Std1003.2
     (``POSIX'').

BSD Experimental                 July 30, 1991                               2