Date and Time formatting

Format specifiers

Excerpt from the strftime man page (please note that not all format specifiers work on all platforms; meaning some do not work on for example Windows):

Ordinary characters placed in the format string are copied to the output without conversion. Conversion specifications are introduced by a '%' character, and terminated by a conversion specifier character, and are replaced in s as follows:

Format specifier	Description
%a	The abbreviated weekday name according to the current locale.
%A	The full weekday name according to the current locale.
%b	The abbreviated month name according to the current locale.
%B	The full month name according to the current locale.
%c	The preferred date and time representation for the current locale.
%C	The century number (year/100) as a 2-digit integer. (SU)
%d	The day of the month as a decimal number (range 01 to 31).
%D	Equivalent to %m/%d/%y. (Yecch --- for Americans only. Americans should note that in other countries %d/%m/%y is rather common. This means that in international context this format is ambiguous and should not be used.) (SU)
%e	Like %d, the day of the month as a decimal number, but a leading zero is replaced by a space. (SU)
%E	Modifier: use alternative format, see below. (SU)
%F	Equivalent to %Y-%m-%d (the ISO 8601 date format). (C99)
%G	The ISO 8601 year with century as a decimal number. The 4-digit year corresponding to the ISO week number (see %V). This has the same format and value as %y, except that if the ISO week number belongs to the previous or next year, that year is used instead. (TZ)
%g	Like %G, but without century, i.e., with a 2-digit year (00-99). (TZ)
%h	Equivalent to %b. (SU)
%H	The hour as a decimal number using a 24-hour clock (range 00 to 23).
%I	The hour as a decimal number using a 12-hour clock (range 01 to 12).
%j	The day of the year as a decimal number (range 001 to 366).
%k	The hour (24-hour clock) as a decimal number (range 0 to 23); single digits are preceded by a blank. (See also %H.) (TZ)
%l	The hour (12-hour clock) as a decimal number (range 1 to 12); single digits are preceded by a blank. (See also %I.) (TZ)
%m	The month as a decimal number (range 01 to 12).
%M	The minute as a decimal number (range 00 to 59).
%n	A newline character. (SU)
%O	Modifier: use alternative format, see below. (SU)
%p	Either 'AM' or 'PM' according to the given time value, or the corresponding strings for the current locale. Noon is treated as 'pm' and midnight as 'am'.
%P	Like %p but in lowercase: 'am' or 'pm' or a corresponding string for the current locale. (GNU)
%r	The time in a.m. or p.m. notation. In the POSIX locale this is equivalent to '%I:%M:%S %p'. (SU)
%R	The time in 24-hour notation (%H:%M). (SU) For a version including the seconds, see %T below.
%s	The number of seconds since the Epoch, i.e., since 1970-01-01 00:00:00 CST. (TZ)
%S	The second as a decimal number (range 00 to 60). (The range is up to 60 to allow for occasional leap seconds.)
%t	A tab character. (SU)
%T	The time in 24-hour notation (%H:%M:%S). (SU)
%u	The day of the week as a decimal, range 1 to 7, Monday being 1. See also %w. (SU)
%U	The week number of the current year as a decimal number, range 00 to 53, starting with the first Sunday as the first day of week 01. See also %V and %W.
%V	The ISO 8601:1988 week number of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the current year, and with Monday as the first day of the week. See also %U and %W. (SU)
%w	The day of the week as a decimal, range 0 to 6, Sunday being 0. See also %u.
%W	The week number of the current year as a decimal number, range 00 to 53, starting with the first Monday as the first day of week 01.
%x	The preferred date representation for the current locale without the time.
%X	The preferred time representation for the current locale without the date.
%y	The year as a decimal number without a century (range 00 to 99).
%Y	The year as a decimal number including the century.
%z	The time-zone as hour offset from UTC. Required to emit RFC 822-conformant dates (using "%a, %d %b %Y %H:%M:%S %z"). (GNU)
%Z	The time zone or name or abbreviation.
%%	A literal '%' character.