NEWSTRFTIME(3)

NAME
strftime - format date and time

SYNOPSIS
#include <time.h>

size_t strftime(char *restrict buf, size_t maxsize,
    char const *restrict format, struct tm const *restrict timeptr);

cc ... -ltz

DESCRIPTION
The strftime function formats the information from timeptr into the buffer buf according to the string pointed to by format.

The format string consists of zero or more conversion specifications and ordinary characters. All ordinary characters are copied directly into the buffer. A conversion specification consists of a percent sign and one other character.

No more than maxsize characters are placed into the array. If the total number of resulting characters, including the terminating null character, is not more than maxsize, strftime returns the number of characters in the array, not counting the terminating null. Otherwise, zero is returned.

Each conversion specification is replaced by the characters as follows which are then copied into the buffer.

%A  is replaced by the locale's full weekday name.

%a  is replaced by the locale's abbreviated weekday name.

%B  is replaced by the locale's full month name.

%b or %h
    is replaced by the locale's abbreviated month name.

%C  is replaced by the century (a year divided by 100 and truncated to an integer) as a decimal number (00–99).

%c  is replaced by the locale's appropriate date and time representation.

%D  is replaced by the date in the format %m/%d/%y.

%d  is replaced by the day of the month as a decimal number (01–31).

%e  is replaced by the day of month as a decimal number (1–31); single digits are preceded by a blank.

%F  is replaced by the date in the format %Y-%m-%d.

%G  is replaced by the ISO 8601 year with century as a decimal number.

%g  is replaced by the ISO 8601 year without century as a decimal number (00–99).

%H  is replaced by the hour (24-hour clock) as a decimal number (00–23).

%I  is replaced by the hour (12-hour clock) as a decimal number (01–12).

%j  is replaced by the day of the year as a decimal number (001–366).

%k  is replaced by the hour (24-hour clock) as a decimal number (0–23); single digits are preceded by a blank.

%l  is replaced by the hour (12-hour clock) as a decimal number (1–12); single digits are preceded by a blank.

%M  is replaced by the minute as a decimal number (00–59).

%m  is replaced by the month as a decimal number (01–12).

%n  is replaced by a newline.

%p  is replaced by the locale's equivalent of either AM or PM.

%R  is replaced by the time in the format %H:%M.

%r  is replaced by the locale's representation of 12-hour clock time using AM/PM notation.

%S  is replaced by the second as a decimal number (00–60).

%s  is replaced by the number of seconds since the Epoch (see newctime(3)).

%T  is replaced by the time in the format %H:%M:%S.

%t  is replaced by a tab.

%U  is replaced by the week number of the year (Sunday as the first day of the week) as a decimal number (00–53).

%u  is replaced by the weekday (Monday as the first day of the week) as a decimal number (1–7).

%V  is replaced by the week number of the year (Monday as the first day of the week) as a decimal number (01–53). If the week containing January 1 has four or more days in the new year, then it is week 1; otherwise it is week 53 of the previous year, and the next week is week 1.

%W  is replaced by the week number of the year (Monday as the first day of the week) as a decimal number (00–53).

%w  is replaced by the weekday (Sunday as the first day of the week) as a decimal number (0–6).

%X  is replaced by the locale's appropriate time representation.

%x  is replaced by the locale's appropriate date representation.

%Y  is replaced by the year with century as a decimal number.

%y  is replaced by the year without century as a decimal number (00–99).

%Z  is replaced by the time zone name, or by the empty string if this is not determinable.

%z  is replaced by the offset from the Prime Meridian in the format +HHMM or -HHMM as appropriate, with positive values representing locations east of Greenwich, or by the empty string if this is not determinable.

%%  is replaced by a single %.

%+  is replaced by the date and time in date(1) format.

SEE ALSO
date(1), getenv(3), newctime(3), newtzset(3), time(2), tzfile(5)