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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 001366
%u day of week from Monday to Sunday 17
%w day of week from Sunday to Saturday 06
Week
%U week number, Sunday as first day of week 0053
%W week number, Monday as first day of week 0053
%V ISO standard week of the year 0153
Month
%m two-digit month number 0112
%h month name, abbreviated Nov
%b month name, localised abbreviation Nov
%B locale's full month, variable length November
Year
%y two-digit year 0099
%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 0099
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 0060 (Includes 60 to accommodate a leap second)
%N nanoseconds 000000000999999999
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:

    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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    Copyright © 2012, 2013 Milo

    Created: February 28, 2012

    Last Updated: November 23, 2013


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