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ctime(3C)

cftime(4)

environ(5)

DATE(1)                              SysV                              DATE(1)



NAME
     date - print and set the date

SYNOPSIS
     date [ mmddhhmm[yy] ] [ -f | -a ] [ +format ]

DESCRIPTION
     If no argument is given, or if the argument begins with +, the current
     date and time are printed.  Otherwise, the current date is set.  The
     first mm is the month number; dd is the day number in the month; hh is
     the hour number (24 hour system); the second mm is the minute number; yy
     is the last 2 digits of the year number and is optional.  For example:

          date

          10080045


     sets the date to Oct 8, 12:45 AM.  The current year is the default if no
     year is mentioned.  The system operates in GMT.  date takes care of the
     conversion to and from local standard and daylight time.  Only the
     superuser can change the date.

     If an argument begins with +, the output of date is under the control of
     the user.  All output fields are of fixed size (zero padded if
     necessary).  Each field descriptor is preceded by % and is replaced in
     the output by its corresponding value.  A single % is encoded by %%.  All
     other characters are copied to the output without change.  The string is
     always terminated with a new-line character.

OPTIONS
     -f        Forces the time to be set backward.

               NOTE   At boot-time, the Domain/OS incorporates the current
                      date and time into the algorithm by which it computes
                      UIDs (unique identifiers).  After using date to set the
                      system time backwards, the user must not reboot the
                      machine until the previous system time has been passed.
                      Rebooting prior to this time will incur the risk that
                      the UID algorithm will incorporate a previously used
                      date and time into new UIDs.  As Domain/OS relies on the
                      uniqueness of UIDs, this can have devasting results.

     -a        If the target time has been set forward, the -a option will
               increment the sytem time at a faster rate until the target time
               (plus the elapsed real time) has been reached.  If the target
               time has been set backward, the -a option will retard
               advancement of the system time, gradually decreasing the
               difference between the two times, until the target time (plus
               the elapsed real time) is met.  This eliminates the possibility
               of duplicate UID generation.

     Field Descriptors:
     n    Insert a new-line character
     t    Insert a tab character
     m    Month of year - 01 to 12
     d    Day of month - 01 to 31
     y    Last 2 digits of year - 00 to 99
     D    Date as mm/dd/yy
     H    Hour - 00 to 23
     M    Minute - 00 to 59
     S    Second - 00 to 59
     T    Time as HH:MM:SS
     j    Day of year - 001 to 366
     w    Day of week - Sunday = 0
     a    Abbreviated weekday - Sun to Sat
     h    Abbreviated month - Jan to Dec
     r    Time in AM/PM Notation
EXAMPLE
     The following input:

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

     would have generated as output:

          DATE: 08/01/76
          TIME: 14:45:05

FILES
     /usr/lib/cftime/*
DIAGNOSTICS
     no permission
               You are not the super-user and you try to change the date.
     bad conversion
               The date set is syntactically incorrect.
     bad format character
               The field descriptor is not recognizable.
NOTES
     To set the date format, or change the existing format, see ctime(3C),
     cftime(4), and environ(5).
WARNING
     Using date to set current date and time backwards can cause the creation
     of objects possessing previously assigned UIDs.
     At boot-time, the Domain/OS incorporates the current date and time into
     the algorithm by which it computes UIDs (unique identifiers).  After
     using date to set the system time backwards, the user must not reboot the
     machine until the previous system time has been passed.  Rebooting prior
     to this time will incur the risk that the UID algorithm will incorporate
     a previously used date and time into new UIDs.  As Domain/OS relies on
     the uniqueness of UIDs, this can have devastating results.
SEE ALSO
     ctime(3C), cftime(4), environ(5).

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