Linux

Manipulation sur les dates

Commande 'date'

Syntaxe :

 $ date [+[format_options]]

Exemples :

 $ date
 Wed Jul 20 16:49:15 CEST 2022
 
 $ date +%Y-%m-%d
 2022-07-20

Options de formatage

Format	Description
+%a	Gives name of the weekday [Mon, Sun, Fri]
+%A	Gives name of the weekday [Monday, Sunday, Friday]
+%b	Gives name of the month [Jan, Feb, Mar]
+%B	Gives name of the month [January, February, March]
+%d	Displays day of the month [05]
+%D	Displays current date MM/DD/YY format [11-01-21]
+%F	Shows date in YYYY-MM-DD format [2021-11-01]
+%H	Shows hour in 24-hour format [22]
+%I	Shows hour in 12-hour format [11]
+%j	Displays the day of the year [001 – 366]
+%m	Displays the number of the month [01-12]
+%M	Displays minutes [00-59]
+%S	Displays seconds [00-59]
+%N	Displays in Nanoseconds
+%T	Displays time as HH:MM:SS [in 24-hour format]
+%u	Day of the week [1-7] 1 is Monday, 6 is Saturday
+%U	Shows week number of the year [00-53]
+%Y	Displays year YYYY [2021]
+%Z	Displays Time zone

Format (avec indicateur)	Description
-d “Yesterday”	Print yesterday's date and time.
-d “tomorrow”	Print Tomorrow date and time.
-d “tomorrow -10 days”	Find what is the date and time before 10 days from now.
-d “last month” “%B”	Find last month.
-d “next month” “%B”	Find next month.
-d “last year” “+%Y”	Find last year.
-d “next year” “+%Y”	Find next year.
-d “Today +2 days” “+%A”	Forecast the weekday

Afficher la date depuis un timestamp

 $ date -d @1381764199
 Mon Oct 14 17:23:19 CEST 2013

Nombre de jours entre 2 dates données

 $ echo $(( ( $(date -d "2022-07-20" "+%s") - $(date -d "2022-01-01" "+%s") ) / 86400))
 199
 # ou
 $ echo $(($((`date +%s --date 01/10/2016`-`date +%s --date 01/10/2015`))/86400)) jours
 365 jours

Identifier une année bissextile

 $ for y in {2000..2010}; do date -d $y-02-29 &>/dev/null && echo "$y est bissextile"; done
 2000 est bissextile
 2004 est bissextile
 2008 est bissextile

Modifier la date et l'heure du système

 $ date --set="Thu Nov 12 13:06:59 IST 2020"
 Thu Nov 12 13:06:59 IST 2020
 $ hwclock --systohc      # synchronise le changement avec l'horloge matérielle