Bash Date Time Format Specifiers

Published: May 21, 2019
Updated: Feb 20, 2022

Given the following bash date, here’s what each specifier will do.

Mon May 27 18:11:12 DST 2019

Specifiers #

Specifier Output Description
%% % a literal %
%a Mon locale’s abbreviated weekday name (e.g., Sun)
%A Monday locale’s full weekday name (e.g., Sunday)
%b May locale’s abbreviated month name (e.g., Jan)
%B May locale’s full month name (e.g., January)
%c Mon May 27 18:11:12 2019 locale’s date and time (e.g., Thu Mar 3 23:05:25 2005)
%C 20 century; like %Y, except omit last two digits (e.g., 20)
%d 27 day of month (e.g., 01)
%D 05/27/19 date; same as %m/%d/%y
%e 27 day of month, space padded; same as %_d
%F 2019-05-27 full date; like %+4Y-%m-%d
%g 19 last two digits of year of ISO week number (see %G)
%G 2019 year of ISO week number (see %V); normally useful only with %V
%h May same as %b
%H 18 hour (00..23)
%I 06 hour (01..12)
%j 147 day of year (001..366)
%k 18 hour, space padded ( 0..23); same as %_H
%l 6 hour, space padded ( 1..12); same as %_I
%m 05 month (01..12)
%M 11 minute (00..59)
%p PM locale’s equivalent of either AM or PM; blank if not known
%P pm like %p, but lower case
%r 06:11:12 PM locale’s 12-hour clock time (e.g., 11:11:04 PM)
%R 18:11 24-hour hour and minute; same as %H:%M
%s 1558998672 seconds since 1970-01-01 00:00:00 UTC
%S 12 second (00..60)
%T 18:11:12 time; same as %H:%M:%S
%u 1 day of week (1..7); 1 is Monday
%U 21 week number of year, with Sunday as first day of week (00..53)
%V 22 ISO week number, with Monday as first day of week (01..53)
%w 1 day of week (0..6); 0 is Sunday
%W 21 week number of year, with Monday as first day of week (00..53)
%x 05/27/19 locale’s date representation (e.g., 12/31/99)
%X 18:11:12 locale’s time representation (e.g., 23:13:48)
%y 19 last two digits of year (00..99)
%Y 2019 year
%z -0500 +hhmm numeric time zone (e.g., -0400)
%Z DST alphabetic time zone abbreviation (e.g., EDT)

Source #

The above markdown table was generated with the following bash script.

#!/bin/bash

specifiers=(
  "%%|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 3 23:05:25 2005)"
  "%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; like %+4Y-%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)"
  "%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|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)"
  "%Z|alphabetic time zone abbreviation (e.g., EDT)"
)

echo
date_string='Mon May 27 18:11:12 DST 2019'
echo "$date_string"
echo

echo "| Specifier | Output | Description |"
echo "| --- | --- | --- |"
for i in "${specifiers[@]}"; do
  specifier="$(echo "$i" | cut -d '|' -f 1)"
  description="$(echo "$i" | cut -d '|' -f 2)"
  output="$(date -d "$date_string" +"$specifier")"
  echo "| \`$specifier\` | \`$output\` | $description |"
done
echo