1.\" Copyright (c) 1989, 1991 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the American National Standards Committee X3, on Information 6.\" Processing Systems. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" from: @(#)strftime.3 5.12 (Berkeley) 6/29/91 37.\" $NetBSD: strftime.3,v 1.5 1998/02/11 18:52:25 kleink Exp $ 38.\" 39.Dd June 29, 1991 40.Dt STRFTIME 3 41.Os 42.Sh NAME 43.Nm strftime 44.Nd format date and time 45.Sh LIBRARY 46.Lb libc 47.Sh SYNOPSIS 48.Fd #include <time.h> 49.Ft size_t 50.Fn strftime "char *buf" "size_t maxsize" "const char *format" "const struct tm *timeptr" 51.Sh DESCRIPTION 52The 53.Fn strftime 54function formats the information from 55.Fa timeptr 56into the buffer 57.Fa buf 58according to the string pointed to by 59.Fa format . 60.Pp 61The 62.Fa format 63string consists of zero or more conversion specifications and 64ordinary characters. 65All ordinary characters are copied directly into the buffer. 66A conversion specification consists of a percent sign 67.Ql % 68and one other character. 69.Pp 70No more than 71.Fa maxsize 72characters will be placed into the array. 73If the total number of resulting characters, including the terminating 74null character, is not more than 75.Fa maxsize , 76.Fn strftime 77returns the number of characters in the array, not counting the 78terminating null. 79Otherwise, zero is returned. 80.Pp 81Each conversion specification is replaced by the characters as 82follows which are then copied into the buffer. 83.Bl -tag -width "xxxx" 84.It Cm \&%A 85is replaced by the locale's full weekday name. 86.It Cm %a 87is replaced by the locale's abbreviated weekday name. 88.It Cm \&%B 89is replaced by the locale's full month name. 90.It Cm \&%b No or Cm \&%h 91is replaced by the locale's abbreviated month name. 92.It Cm \&%C 93is replaced by the century (a year divided by 100 and truncated to an integer) 94as a decimal number [00,99]. 95.It Cm \&%c 96is replaced by the locale's appropriate date and time representation. 97.It Cm \&%D 98is replaced by the date in the format 99.Dq Li %m/%d/%y . 100.It Cm \&%d 101is replaced by the day of the month as a decimal number [01,31]. 102.It Cm \&%e 103is replaced by the day of month as a decimal number [1,31]; 104single digits are preceded by a blank. 105.It Cm \&%H 106is replaced by the hour (24-hour clock) as a decimal number [00,23]. 107.It Cm \&%I 108is replaced by the hour (12-hour clock) as a decimal number [01,12]. 109.It Cm \&%j 110is replaced by the day of the year as a decimal number [001,366]. 111.It Cm \&%k 112is replaced by the hour (24-hour clock) as a decimal number [0,23]; 113single digits are preceded by a blank. 114.It Cm \&%l 115is replaced by the hour (12-hour clock) as a decimal number [1,12]; 116single digits are preceded by a blank. 117.It Cm \&%M 118is replaced by the minute as a decimal number [00,59]. 119.It Cm %m 120is replaced by the month as a decimal number [01,12]. 121.It Cm %n 122is replaced by a newline. 123.It Cm %p 124is replaced by the locale's equivalent of either 125.Dq Tn AM 126or 127.Dq Tn PM . 128.It Cm \&%R 129is replaced by the time in the format 130.Dq Li %H:%M . 131.It Cm \&%r 132is replaced by the locale's representation of 12-hour clock time 133using AM/PM notation. 134.It Cm \&%T 135is replaced by the time in the format 136.Dq Li %H:%M:%S . 137.It Cm \&%t 138is replaced by a tab. 139.It Cm \&%S 140is replaced by the second as a decimal number [00,61]. 141.It Cm %s 142is replaced by the number of seconds since the Epoch, UCT (see 143.Xr mktime 3 ) . 144.It Cm \&%U 145is replaced by the week number of the year (Sunday as the first day of 146the week) as a decimal number [00,53]. 147.It Cm \&%u 148is replaced by the weekday (Monday as the first day of the week) 149as a decimal number [1,7]. 150.It Cm \&%V 151is replaced by the week number of the year (Monday as the first day of 152the week) as a decimal number [01,53]. If the week containing January 1531 has four or more days in the new year, then it is week 1; otherwise 154it is week 53 of the previous year, and the next week is week 1. 155.It Cm \&%W 156is replaced by the week number of the year (Monday as the first day of 157the week) as a decimal number [00,53]. 158.It Cm \&%w 159is replaced by the weekday (Sunday as the first day of the week) 160as a decimal number [0,6]. 161.It Cm \&%X 162is replaced by the locale's appropriate time representation. 163.It Cm \&%x 164is replaced by the locale's appropriate date representation. 165.It Cm \&%Y 166is replaced by the year with century as a decimal number. 167.It Cm \&%y 168is replaced by the year without century as a decimal number [00,99]. 169.It Cm \&%Z 170is replaced by the time zone name. 171.It Cm %% 172is replaced by 173.Ql % . 174.El 175.Sh SEE ALSO 176.Xr date 1 , 177.Xr ctime 3 , 178.Xr strptime 3 , 179.Xr printf 1 , 180.Xr printf 3 181.Sh STANDARDS 182The 183.Fn strftime 184function 185conforms to 186.St -ansiC . 187The 188.Ql \&%C , 189.Ql \&%D , 190.Ql \&%e , 191.Ql \&%h , 192.Ql \&%k , 193.Ql \&%l , 194.Ql \&%n , 195.Ql \&%r , 196.Ql \&%R , 197.Ql \&%s . 198.Ql \&%t , 199.Ql \&%T , 200.Ql \&%u , 201and 202.Ql \&%V 203conversion specifications are extensions. 204.Sh BUGS 205There is no conversion specification for the phase of the moon. 206