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@(#)date.1 6.6 (Berkeley) 04/01/87

C 4 date - print and set the date date "[-nu] [-d dst] [-t minutes_west] [yymmddhhmm [" . "ss] ]" If no arguments are given, the current date and time are printed. Providing an argument will set the desired date; only the superuser can set the date. The -d and -t flags set the kernel's values for daylight savings time and minutes west of GMT. If dst is non-zero, future calls to gettimeofday(2) will return a non-zero tz_dsttime. Minutes_west provides the number of minutes returned by future calls to gettimeofday(2) in tz_minuteswest. The -u flag is used to display or set the date in GMT (universal) time. yy represents the last two digits of the year; the first mm is the month number; dd is the day number; hh is the hour number (24 hour system); the second mm is the minute number; . ss is optional and represents the seconds. For example: date 8506131627

sets the date to June 13 1985, 4:27 PM. The year, month and day may be omitted; the default values will be the current ones. The system operates in GMT. Date takes care of the conversion to and from local standard and daylight-saving time.

If timed(8) is running to synchronize the clocks of machines in a local area network, date sets the time globally on all those machines unless the -n option is given.

/usr/adm/wtmp to record time-setting. In /usr/adm/messages, date records the name of the user setting the time. gettimeofday(2), utmp(5), timed(8),

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

Exit status is 0 on success, 1 on complete failure to set the date, and 2 on successfully setting the local date but failing 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.

The system attempts to keep the date in a format closely compatible with VMS. VMS, however, uses local time (rather than GMT) and does not understand daylight-saving time. Thus, if you use both UNIX and VMS, VMS will be running on GMT.