Returns a string formatted according to the given format string
using the given timestamp or the current
local time if no timestamp is given. Month and weekday names and
other language dependent strings respect the current locale set
with setlocale().
The following conversion specifiers are recognized in the format
string:
%a - abbreviated weekday name according to the current locale
%A - full weekday name according to the current locale
%b - abbreviated month name according to the current locale
%B - full month name according to the current locale
%c - preferred date and time representation for the current
locale
%C - century number (the year divided by 100 and truncated to
an integer, range 00 to 99)
%d - day of the month as a decimal number (range 00 to 31)
%D - same as %m/%d/%y
%e - day of the month as a decimal number, a single digit is
preceded by a space (range ' 1' to '31')
%h - same as %b
%H - hour as a decimal number using a 24-hour clock (range 00
to 23)
%I - hour as a decimal number using a 12-hour clock (range 01
to 12)
%j - day of the year as a decimal number (range 001 to 366)
%m - month as a decimal number (range 1 to 12)
%M - minute as a decimal number
%n - newline character
%p - either `am' or `pm' according to the given time value, or
the corresponding strings for the current locale
%r - time in a.m. and p.m. notation
%R - time in 24 hour notation
%S - second as a decimal number
%t - tab character
%T - current time, equal to %H:%M:%S
%u - weekday as a decimal number [1,7], with 1 representing
Monday
%U - week number of the current year as a decimal number,
starting with the first Sunday as the first day of the first
week
%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.
%W - week number of the current year as a decimal number,
starting with the first Monday as the first day of the first
week
%w - day of the week as a decimal, Sunday being 0
%x - preferred date representation for the current locale
without the time
%X - preferred time representation for the current locale
without the date
%y - year as a decimal number without a century (range 00 to
99)
%Y - year as a decimal number including the century
%Z - time zone or name or abbreviation
%% - a literal `%' character
This example works if you have the respective locales installed
in your system.