How to set / find system date and time in Linux

Inorder to set/find the system date and time in Linux we use the date command. The syntax of date command is

date [options] [+Format]

Some important Formats and their interpretation

%%	a literal %
%a	locale's abbreviated weekday name (e.g., Sun)
%A	locale's full weekday name (e.g., Sunday)
%b	locale's abbreviated month name (e.g., Jan)
%B	locale's full month name (e.g., January)
%c	locale's date and time (e.g., Thu Mar
%C	century; like %Y, except omit last two digits (e.g., 20)
%d	day of month (e.g., 01)
%D	date; same as %m/%d/%y
%e	day of month, space padded; same as %_d
%F	full date; same as %Y-%m-%d
%g	last two digits of year of ISO week number (see %G)
%G	year of ISO week number (see %V); normally useful only with %V
%h	same as %b
%H	hour (00..23)
%I	hour (01..12)
%j	day of year (001..366)
%k	hour, space padded ( 0..23); same as %_H
%l	hour, space padded ( 1..12); same as %_I
%m	month (01..12)
%M	minute (00..59)
%n	a newline
%N	nanoseconds (000000000..999999999)
%p	locale's equivalent of either AM or PM; blank if not known
%P	like %p, but lower case
%r	locale's 12-hour clock time (e.g., 11:11:04 PM)
%R	24-hour hour and minute; same as %H:%M
%s	seconds since 1970-01-01 00:00:00 UTC
%S	second (00..60)
%t	a tab
%T	time; same as %H:%M:%S
%u	day of week (1..7); 1 is Monday
%U	week number of year, with Sunday as first day of week (00..53)
%V	ISO week number, with Monday as first day of week (01..53)
%w	day of week (0..6); 0 is Sunday
%W	week number of year, with Monday as first day of week (00..53)
%x	locale's date representation (e.g., 12/31/99)
%X	locale's time representation (e.g., 23:13:48)
%y	last two digits of year (00..99)
%Y	year
%z	+hhmm numeric time zone (e.g., -0400)

 

 Examples of date command

#1) To print the current system date and time, type

date

Sample output

Mon Nov 17 14:48:22 IST 2014

#2) To set system date and time to 18 Oct 2014 17:00, type

(a)Method 1

date '111817002014'

where first 2 numbers (11) represent the  month, the second 2 represent the day (18), the third 2 numbers (17)repersent the hour in 24-hour format, the fourth 2 numbers (00) represents the minute and the remaining four numbers (2014) represents the year
Sample output

 Tue Nov 18 17:00:00 IST 2014 2014

(b)Method 2

date -s 'Tue Nov 18 17:00:00 IST 2014'

Sample output

Tue Nov 18 17:00:03 IST  2014

#3) To print the current system date and time in dd/mm/yyyy hh:mm:ss format, type

date +%d/%m/%Y' '%H:%M:%S

Sample output

17/11/2014 15:02:14

#4) To print the past and future system date and time

In addition to  displaying current system date and time, date command can be used to print the past and future date and time also. The below screen shot of a Linux terminal depicts the ability of date command to print past date and time with respect to the current system date and time

The below screen shot of a Linux terminal depicts the ability of date command to print future date and time with respect to the current system date and time

For more details on date command see the man pages