newstrftime.3

.\" strftime man page
.\"
.\" Based on the UCB file whose corrected copyright information appears below.
.\" Copyright 1989, 1991 The Regents of the University of California.
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.\" This code is derived from software contributed to Berkeley by
.\" the American National Standards Committee X3, on Information
.\" Processing Systems.
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.\"     from: @(#)strftime.3	5.12 (Berkeley) 6/29/91
.\"	$Id: strftime.3,v 1.4 1993/12/15 20:33:00 jtc Exp $
.\"
.TH NEWSTRFTIME 3
.SH NAME
strftime \- format date and time
.SH SYNOPSIS
.nf
.ie \n(.g .ds - \f(CW-\fP
.el ds - \-
.B #include <time.h>
.PP
.B "size_t strftime(char *restrict buf, size_t maxsize,"
.B "    char const *restrict format, struct tm const *restrict timeptr);"
.PP
.B cc ... \-ltz
.fi
.SH DESCRIPTION
.ie '\(en'' .ds en \-
.el .ds en \(en
.ie '\(lq'' .ds lq \&"\"
.el .ds lq \(lq\"
.ie '\(rq'' .ds rq \&"\"
.el .ds rq \(rq\"
.de q
\\$3\*(lq\\$1\*(rq\\$2
..
The
.I strftime
function formats the information from
.I timeptr
into the buffer
.I buf
according to the string pointed to by
.IR format .
.PP
The
.I 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
.Ql %
and one other character.
.PP
No more than
.I maxsize
characters are placed into the array.
If the total number of resulting characters, including the terminating
null character, is not more than
.IR maxsize ,
.I strftime
returns the number of characters in the array, not counting the
terminating null.
Otherwise, zero is returned.
.PP
Each conversion specification is replaced by the characters as
follows which are then copied into the buffer.
.TP
%A
is replaced by the locale's full weekday name.
.TP
%a
is replaced by the locale's abbreviated weekday name.
.TP
%B
is replaced by the locale's full month name.
.TP
%b or %h
is replaced by the locale's abbreviated month name.
.TP
%C
is replaced by the century (a year divided by 100 and truncated to an integer)
as a decimal number (00\*(en99).
.TP
%c
is replaced by the locale's appropriate date and time representation.
.TP
%D
is replaced by the date in the format %m/%d/%y.
.TP
%d
is replaced by the day of the month as a decimal number (01\*(en31).
.TP
%e
is replaced by the day of month as a decimal number (1\*(en31);
single digits are preceded by a blank.
.TP
%F
is replaced by the date in the format %Y\*-%m\*-%d.
.TP
%G
is replaced by the ISO 8601 year with century as a decimal number.
.TP
%g
is replaced by the ISO 8601 year without century as a decimal number (00\*(en99).
.TP
%H
is replaced by the hour (24-hour clock) as a decimal number (00\*(en23).
.TP
%I
is replaced by the hour (12-hour clock) as a decimal number (01\*(en12).
.TP
%j
is replaced by the day of the year as a decimal number (001\*(en366).
.TP
%k
is replaced by the hour (24-hour clock) as a decimal number (0\*(en23);
single digits are preceded by a blank.
.TP
%l
is replaced by the hour (12-hour clock) as a decimal number (1\*(en12);
single digits are preceded by a blank.
.TP
%M
is replaced by the minute as a decimal number (00\*(en59).
.TP
%m
is replaced by the month as a decimal number (01\*(en12).
.TP
%n
is replaced by a newline.
.TP
%p
is replaced by the locale's equivalent of either AM or PM.
.TP
%R
is replaced by the time in the format %H:%M.
.TP
%r
is replaced by the locale's representation of 12-hour clock time
using AM/PM notation.
.TP
%S
is replaced by the second as a decimal number (00\*(en60).
.TP
%s
is replaced by the number of seconds since the Epoch (see newctime(3)).
.TP
%T
is replaced by the time in the format %H:%M:%S.
.TP
%t
is replaced by a tab.
.TP
%U
is replaced by the week number of the year (Sunday as the first day of
the week) as a decimal number (00\*(en53).
.TP
%u
is replaced by the weekday (Monday as the first day of the week)
as a decimal number (1\*(en7).
.TP
%V
is replaced by the week number of the year (Monday as the first day of
the week) as a decimal number (01\*(en53).  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.
.TP
%W
is replaced by the week number of the year (Monday as the first day of
the week) as a decimal number (00\*(en53).
.TP
%w
is replaced by the weekday (Sunday as the first day of the week)
as a decimal number (0\*(en6).
.TP
%X
is replaced by the locale's appropriate time representation.
.TP
%x
is replaced by the locale's appropriate date representation.
.TP
%Y
is replaced by the year with century as a decimal number.
.TP
%y
is replaced by the year without century as a decimal number (00\*(en99).
.TP
%Z
is replaced by the time zone abbreviation,
or by the empty string if this is not determinable.
.TP
%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.
The numeric time zone abbreviation \*-0000 is used when the time is
Universal Time
but local time is indeterminate; by convention this is used for
locations while uninhabited, and corresponds to a zero offset when the
time zone abbreviation begins with
.q "\*-" .
.TP
%%
is replaced by a single %.
.TP
%+
is replaced by the date and time in date(1) format.
.SH SEE ALSO
date(1),
getenv(3),
newctime(3),
newtzset(3),
time(2),
tzfile(5)