date

What is date?

On Unix-like operating systems, the date command is used to print out, or change the value of, the system's time and date information.

How to use date

# syntax
date <options>

##### set date an time using -set option
date # output : Sun May 20 20:09:31 PDT 2013

date -s "Sun May 20 21:00:00 PDT 2013" # output : Sun May 20 21:00:00 PDT 2013

date # output : Sun May 20 21:00:05 PDT 2013

##### output from a string
date --date="12/2/2014" # output : Tue Dec  2 00:00:00 PST 2014
date --date="2 Feb 2014" # output : Sun Feb  2 00:00:00 PST 2014
date --date="Feb 2 2014" # output : Sun Feb  2 00:00:00 PST 2014

##### output from a string, with date and time
date --date="Feb 2 2014 13:12:10" # output : Sun Feb  2 13:12:10 PST 2014

##### read date patterns from a file using -file option
cat datefile
# output underneath
Sept 9 1986
Aug 23 1987

date --file=datefile
# output underneath
Tue Sep  9 00:00:00 PDT 1986
Sun Aug 23 00:00:00 PDT 1987

##### Display universal time using -u option
date # output : Mon May 20 22:07:53 PDT 2013
date -u # output : Tue May 21 05:07:55 UTC 2013 

Various date commands

# syntax
date + %<format-option>

##### examples 

date +%a # output : Mon
date +%F # output : 2020-09-14
date +%m # output : 09

Format options	Purpose of Option	Output
date +%a	Displays Weekday name in short (like Mon, Tue, Wed)	Thu
date +%A	Displays Weekday name in full short (like Monday, Tuesday)	Thursday
date +%b	Displays Month name in short (like Jan, Feb, Mar )	Feb
date +%B	Displays Month name in full short (like January, February)	February
date +%d	Displays Day of month (e.g., 01)	07
date +%D	Displays Current Date; shown in MM/DD/YY	02/07/13
date +%F	Displays Date; shown in YYYY-MM-DD	2013-02-07
date +%H	Displays hour in (00..23) format	23
date +%I	Displays hour (01..12) format	11
date +%j	Displays day of year (001..366)	038
date +%m	Displays month (01..12)	02
date +%M	Displays minute (00..59)	44
date +%S	Displays second (00..60)	17
date +%N	Displays nanoseconds (000000000..999999999)	573587606
date +%T	Displays time; shown as HH:MM:SS Note: Hours in 24 Format	23:44:17
date +%u	Displays day of week (1..7); 1 is Monday	4
date +%U	Displays week number of year, with Sunday as first day of week (00..53)	05
date +%Y	Displays full year i.e. YYYY	2020
date +%Z	alphabetic time zone abbreviation (e.g., EDT)	IS