date

summary

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

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

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
$

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).