— display or
set date and time
When invoked without arguments, the date
displays the current date and time. Otherwise, depending on the options
will set the date and time or
print it in a user-defined way.
Changing the system date has some risks, as described in
. Only the
superuser may change the date.
The options are as follows:
- Use the
adjtime(2) call to
gradually skew the local time to the desired time rather than just
- Set the system's value for Daylight Saving Time. If
dst is non-zero, future calls to
return a non-zero value for
- Parse the provided date and time and display the result
without changing the clock.
- Print out (in specified format) the date and time
represented by seconds from the
- 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
- Display or set the date in UTC (Coordinated Universal)
- Just before printing the time, change to the specified
timezone; see the description of
below. This can be used with -j to easily
convert time specifications from one zone to another.
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
’) character is always output after
the characters specified by the format string. The format string for the
default display is:
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:
- Year. If yy is specified, but cc is not, a value for yy
between 69 and 99 results in a cc value of 19. Otherwise, a cc value of 20
- Month: a number from 1 to 12.
- Day: a number from 1 to 31.
- Hour: a number from 0 to 23.
- Minute: a number from 0 to 59.
- Second: a number from 0 to 60 (permitting a leap second),
preceded by a period.
Everything but the minute is optional.
Time changes for Daylight Saving Time, standard time, leap seconds, and leap
years are handled automatically.
- The time zone to use when parsing or 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
- record of date resets and time changes
- record of the user setting the time
utility exits 0 on success,
and >0 if an error occurs.
Display the date using the specified format string:
$ date "+DATE: %Y-%m-%d%nTIME: %H:%M:%S"
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
utility is compliant with the
IEEE Std 1003.1-2008
The flags [-adjrtz
well as the conversion specifiers ‘
’, are extensions to that
This implementation requires the traditional BSD
format, [[[[[cc]yy]mm]dd]HH]MM[.SS], which differs from the X/Open System
Interfaces option of the IEEE Std 1003.1-2008
command appeared in
Version 1 AT&T UNIX