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date

summary

����This subchapter looks at date, a UNIX (and Linux) command.

����date is used to set or view the system date and time.

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date

����This subchapter looks at date, a UNIX (and Linux) command.

����date is used to set or view the system date and time.

����$ date
����Mon Sep��3 00:56:17 PDT 2012
����$

����The format for the output is: day of the week, month, day of the month, 24 hour time, time zone, year.

formatted output

����Display the time and/or date with formatting by including formatting options (which can be used to set variables to a specific format).

����$ date '+DATE: %m/%d/%y%nTIME: %H:%M:%S'
����DATE: 11/23/13
����TIME: 22:12:19
����$

����Setting a variable with the current date:

����$ NOW=$(date +"%m/%d/%Y")
����$ echo $NOW
����11/23/2013
����$

Format specifiers (format string starts with +)

Specifier	Description	Values or example
Day
%a	weekday, abbreviated	Sun
%A	weekday, full	Sunday
%d	day of the month, two digits, zero filled	08
%e	day of the month	8
%j	day of year, zero filled	001�366
%u	day of week from Monday to Sunday	1�7
%w	day of week from Sunday to Saturday	0�6
Week
%U	week number, Sunday as first day of week	00�53
%W	week number, Monday as first day of week	00�53
%V	ISO standard week of the year	01�53
Month
%m	two-digit month number	01�12
%h	month name, abbreviated	Nov
%b	month name, localised abbreviation	Nov
%B	locale's full month, variable length	November
Year
%y	two-digit year	00�99
%Y	four-digit year	2013
%g	two-digit year corresponding to the�%V week number
%G	four-digit year corresponding to the�%V week number
Century
%C	two century digits from year	00�99
Date
%D	mm/dd/yy	11/24/13
%x	locale's date representation	11/24/2013
%F	%Y-%m-%d	2013-11-24
Hours
%l	hour (12 hour)	4
%I	hour (12 hour), zero-filled	04
%k	hour (24 hour)	4
%H	hour (24 hour), zero-padded	04
%p	locale's upper case AM or PM (blank in many locales)	AM
%P	locale's lower case am or pm	am
Minutes
%M	two-digit minute number	05
Seconds
%s	seconds since 00:00:00 1970-01-01 UTC (Unix epoch)	1385265929
%S	two-digit second number	00�60 (Includes 60 to accommodate a leap second)
%N	nanoseconds	000000000�999999999
Time
%r	hours, minutes, seconds (12-hour clock)	04:05:29 AM
%R	hours, minutes (24 hour clock)	04:05
%T	hours, minutes, seconds (24-hour clock)	04:05:29
%X	locale's time representation	11:07:26 AM
Date and time
%c	locale's date and time	Sat Nov 04 12:02:33 EST 1989
Time zone
%z	RFC-822 style numeric time zone	-0500
%Z	time zone name; nothing if no time zone is determinable	EST, EDT

literals: ���� %n newline ���� %% percent ���� %t horizontal tab

����By default, date normally fills numeric fields with zeroes. GNU date, but not BSD date, recognizes a modifier between the per cent sign (%) and the format specifier:

• hyphen (-): do not fill the field
• underscore (_): pad the field with spaces

����TZ Specifies the time zone, unless overridden by command line parameters. If neither is specified, the setting from /etc/localtime is used.

setting time and date

����Only the root or superuser an set the system date and time. In Mac OS X, you can use the clock system preferences t set the time and date. In Ubuntu-based Linux, you can click on the clock and select Time and Date settings from the menu or click on the System menu, select Adminsitration, select Time and Date.

����Set the time to noon:

����$ date 1200
����$

����Set the time to 3:30:30 a.m.:

����$ date 0330.30
����$

����Set the date to October 31st (Halloween) at 3:30 a.m.:

����$ date 10310330
����$

other

����On November 8, 2010, Ramesh Natarajan named this the number 49 most frequently used UNIX/Linux command at this web page 50 Most Frequently Used UNIX / Linux Commands (With Examples).

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