| DATE(1) |
AerieBSD 1.0 Refernce Manual |
DATE(1) |
NAME
date —
display or set date and time
SYNOPSIS
date
[-ajnu]
[-d dst]
[-r seconds]
[-t minutes_west]
[-+]
.Sm off
.Oo Oo Oo Oo Oo Oo
ccOc
yyOc
mmOc
ddOc
HHOc
MM[\&.SSOc]
.Sm on
DESCRIPTION
When invoked without arguments, the
date
utility displays the current date and time.
Otherwise, depending on the options specified,
date
will set the date and time or print it in a user-defined way.
Only the superuser may set the date.
The options are as follows:
- -a
-
Use the
adjtime(2)
call to gradually skew the local time to the
remote time rather than just hopping.
- -d dst
-
Set the system's value for Daylight Saving Time.
If
dst
is non-zero, future calls
to
gettimeofday(2)
will return a non-zero value for
tz_dsttime.
- -j
-
Parse the provided date and time and display the result without changing
the clock.
- -n
-
By default,
if the
timed(8)
daemon is running,
date
sets the time on all of the machines in the local group.
The
-n
option suppresses this behavior and causes the time to be set only on the
current machine.
- -r seconds
-
Print out (in specified format) the date and time represented by
seconds
from the Epoch.
- -t minutes_west
-
Set the system's value 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 UTC (Coordinated 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.
A newline
("\en")
character is always output after the characters specified by
the format string.
The format string for the default display is:
%a %b %e %H:%M:%S %Z %Y
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 is:
- ccyy
-
Year:
the first two digits (representing the century) may be omitted
for non-ambiguous years (1969\-2068).
- 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
-
Minute: a number from 0 to 59.
- SS
-
Second: a number from 0 to 61 (59 plus a maximum of two leap seconds).
Everything but the minute is optional.
Time changes for Daylight Saving Time, standard time, leap seconds,
and leap years are handled automatically.
ENVIRONMENT
- TZ
-
The time zone to use when displaying dates.
See
environ(7)
for more information.
If this variable is not set, the time zone is determined based on
/etc/localtime,
which the administrator adjusts using
the
-l
option of
zic(8).
FILES
- /var/log/wtmp
-
record of date resets and time changes
- /var/log/messages
-
record of the user setting the time
EXAMPLES
Display the date using the specified format string:
$ date "+DATE: %Y-%m-%d%nTIME: %H:%M:%S"
DATE: 1987-11-21
TIME: 13:36:16
Set the date to
June 13, 1985, 4:27 PM:
# date 198506131627
Set the time to
2:32 PM,
without modifying the date:
# date 1432
DIAGNOSTICS
Exit status is 0 on success, 1 if unable to set the date, and 2
if able to set the local date, but unable to set it globally.
Occasionally, when
timed(8)
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(8)
fails.
SEE ALSO
adjtime(2),
gettimeofday(2),
strftime(3),
utmp(5),
ntpd(8),
rdate(8),
timed(8)
.Rs
.%T "TSP: The Time Synchronization Protocol for UNIX 4.3BSD"
.%A R. Gusella
.%A S. Zatti
.Re
STANDARDS
The
date
utility is compliant with the
specification.
The flags
[-adjnrt]
are extensions to that specification.
HISTORY
A
date
command appeared in
Version 1 AT&T UNIX.
| AerieBSD 1.0 Reference Manual |
August 26 2008 |
DATE(1) |