- Date (Unix)
The
Unix date command displays the time and date. The super-user can use it to set thesystem clock .Usage
With no options, the date command displays the current date and time, including the abbreviated day name, abbreviated month name, day of the month, the time separated by colons, the timezone name, and the year. For example: $date Fri Jul 27 14:12:06 EDT 2007
Formatting
To format a date provide a string beginning with + .
literals: %n newline %% percent %t horizontal tab
By default, date pads numeric fields with zeroes.
GNU date, but not BSD date, recognizes - (hyphen) do not pad the field and _ (underscore) pad the field with spaces between % and a numeric directive.
TZ Specifies the timezone, unless overridden by command line parameters.If neither is specified, the setting from /etc/localtime is used.
Options
-d, -de="string" display time described by "string", not "now".
-e="datefile" like de once for each line of "datefile"
-s, --set="string" set time described by "string"
-n don't synchronize the clocks on groups of machines using the utility timed(8). By default, if timed is running, date will set the time on all of the machines in the local group. -n inhibites that.
-u Display or set the date in UTC (universal) time.
date [-u|--utc|--universal] [MMDDhhmm [CC] YY]
.ss The only valid option for the this form specifies Coordinated Universal Time.-u GMT ex: Sat Feb 5 14:49:42 GMT 2005
--utc, --universal Coordinated Universal Time local TZ Sat Feb 5 09:49:59 EST 2005
-ITIMESPEC, --iso-8601 [=TIMESPEC] output date/time in ISO 8601 format. TIMESPEC=date for date only, hours, minutes, or seconds for date and time to the indicated precision.
--iso-8601 without TIMESPEC defaults to `date'.
-R, --rfc-822 output RFC-822 compliant date stringexample: Sat Feb 5 09:50:23 EST 2005
--help
The
Single Unix Specification (SUS) mandates only one option: -u, where the date and time is printed as if the timezone was UTC+0. Other Unix and Unix-like systems provide extra options.Examples
date "+%-m/%-d/%y" 7/4/06
date "+%Y%m%d" 20060704
To assign the time to a variable START=`date '+%r'` echo $START 03:06:02 PM sleep 5 echo $START 03:06:02 PMN.B. the variable has the time when it was assigned.
Yesterday assigned to variable DATE=$(date -d yesterday +"%Y%m%d") echo $DATE 20060704
Other valid time strings date +"%Y%m%d" -d sunday 20060709 date +"%Y%m%d" -d last-sunday 20060702 date +"%Y%m%d" -d last-week 20060627 date +"%Y%m%d" -d last-month 20060604 date +"%Y%m%d" -d last-year 20050704 date +"%Y%m%d" -d next-week 20060711 date +"%Y%m%d" -d next-month 20060804 date +"%Y%m%d" -d next-year 20070704
Setting the date
The
XSI extension to the SUS specifies that the date command can also be used to set the date. The new date is specified as an option to date in the format MMddhhmm [cc] yy] , where MM specifies the two-digit numeric month, dd specifies the two-digit numeric day, hh specifies the two-digit numeric hour, mm specifies the two-digit numeric minutes. Optionally cc specifies the first two digits of the year, and yy specifies the last two digits of the year.Other Unix and Unix-like systems may set different options or date formats for date, for example, on some systems to set the current date and time to
September 8 ,2004 01:22 you type:date --set="20040908 01:22"
See also
*
List of Unix programs
*Unix time , i.e. number of seconds elapsed since midnight UTC of January 1, 1970Epoch
*time and date
*Cron process for scheduling jobs to run on a given date.External links
*man|1|date|Linux|print or set the system date and time
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