Copyright (c) 1980 Regents of the University of California. All rights reserved. The Berkeley software License Agreement specifies the terms and conditions for redistribution. @(#)date.1 6.6 (Berkeley) 04/01/87 DATE 1 ""
C 4 NAME
date - print and set the date
SYNOPSIS
date "[-nu] [-d dst] [-t minutes_west] [yymmddhhmm [" . "ss] ]" DESCRIPTION
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.
FILES
/
usr/
adm/
wtmp to record time-setting.
In /
usr/
adm/
messages,
date records the name of the user
setting the time.
SEE ALSO
gettimeofday(2), utmp(5), timed(8),
TSP: The Time Synchronization Protocol for UNIX 4.3BSD,
R. Gusella and S. Zatti
DIAGNOSTICS
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.
BUGS
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.