NAME
strftime - format date and time

SYNOPSIS
#include <sys/types.h>
#include <time.h>
#include <string.h>

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

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 will be 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 full weekday name.

%a is replaced by the abbreviated weekday name, where the
abbreviation is the first three characters.

%B is replaced by the full month name.

%b or %h
is replaced by the abbreviated month name, where the
abbreviation is the first three characters.

%C is equivalent to "%a %b %e %H:%M:%S %Y" (the format produced
by asctime(3).

%c is equivalent to "%m/%d/%y".

%D is replaced by the date in the format "mm/dd/yy".

%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.

%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 either "AM" or "PM" as appropriate.

%R is equivalent to "%H:%M".

%r is equivalent to "%I:%M:%S %p".

%t is replaced by a tab.

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

%s is replaced by the number of seconds since the Epoch, UCT (see

%T or %X
is equivalent to "%H:%M:%S".

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

%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 equivalent to "%m/%d/%y %H:%M:%S".

%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.

%% is replaced by ‘%’.

SEE ALSO
date(1), ctime(3), printf(1), printf(3)

STANDARDS
The strftime function conforms to ANSI X3.159-1989. The ‘%s’
conversion specification is an extension.