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.\" $Id: strftime.3,v 1.2 1997/05/25 19:34:44 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 SYNOPSIS 46.Fd #include <time.h> 47.Ft size_t 48.Fn strftime "char *buf" "size_t maxsize" "const char *format" "const struct tm *timeptr" 49.Sh DESCRIPTION 50The 51.Fn strftime 52function formats the information from 53.Fa timeptr 54into the buffer 55.Fa buf 56according to the string pointed to by 57.Fa format . 58.Pp 59The 60.Fa format 61string consists of zero or more conversion specifications and 62ordinary characters. 63All ordinary characters are copied directly into the buffer. 64A conversion specification consists of a percent sign 65.Ql % 66and one other character. 67.Pp 68No more than 69.Fa maxsize 70characters will be placed into the array. 71If the total number of resulting characters, including the terminating 72null character, is not more than 73.Fa maxsize , 74.Fn strftime 75returns the number of characters in the array, not counting the 76terminating null. 77Otherwise, zero is returned. 78.Pp 79Each conversion specification is replaced by the characters as 80follows which are then copied into the buffer. 81.Bl -tag -width "xxxx" 82.It Cm \&%A 83is replaced by the locale's full weekday name. 84.It Cm %a 85is replaced by the locale's abbreviated weekday name. 86.It Cm \&%B 87is replaced by the locale's full month name. 88.It Cm \&%b No or Cm \&%h 89is replaced by the locale's abbreviated month name. 90.It Cm \&%C 91is replaced by the century (a year divided by 100 and truncated to an integer) 92as a decimal number (00-99). 93.It Cm \&%c 94is replaced by the locale's appropriate date and time representation. 95.It Cm \&%D 96is replaced by the date in the format 97.Dq Li %m/%d/%y . 98.It Cm \&%d 99is replaced by the day of the month as a decimal number (01-31). 100.It Cm \&%e 101is replaced by the day of month as a decimal number (1-31); 102single digits are preceded by a blank. 103.It Cm \&%H 104is replaced by the hour (24-hour clock) as a decimal number (00-23). 105.It Cm \&%I 106is replaced by the hour (12-hour clock) as a decimal number (01-12). 107.It Cm \&%j 108is replaced by the day of the year as a decimal number (001-366). 109.It Cm \&%k 110is replaced by the hour (24-hour clock) as a decimal number (0-23); 111single digits are preceded by a blank. 112.It Cm \&%l 113is replaced by the hour (12-hour clock) as a decimal number (1-12); 114single digits are preceded by a blank. 115.It Cm \&%M 116is replaced by the minute as a decimal number (00-59). 117.It Cm %m 118is replaced by the month as a decimal number (01-12). 119.It Cm %n 120is replaced by a newline. 121.It Cm %p 122is replaced by the locale's equivalent of either 123.Dq Tn AM 124or 125.Dq Tn PM . 126.It Cm \&%R 127is replaced by the time in the format 128.Dq Li %H:%M . 129.It Cm \&%r 130is replaced by the locale's representation of 12-hour clock time 131using AM/PM notation. 132.It Cm \&%T 133is replaced by the time in the format 134.Dq Li %H:%M:%S . 135.It Cm \&%t 136is replaced by a tab. 137.It Cm \&%S 138is replaced by the second as a decimal number (00-60). 139.It Cm %s 140is replaced by the number of seconds since the Epoch, UCT (see 141.Xr mktime 3 ) . 142.It Cm \&%U 143is replaced by the week number of the year (Sunday as the first day of 144the week) as a decimal number (00-53). 145.It Cm \&%u 146is replaced by the weekday (Monday as the first day of the week) 147as a decimal number (1-7). 148.It Cm \&%V 149is replaced by the week number of the year (Monday as the first day of 150the week) as a decimal number (01-53). If the week containing January 1511 has four or more days in the new year, then it is week 1; otherwise 152it is week 53 of the previous year, and the next week is week 1. 153.It Cm \&%W 154is replaced by the week number of the year (Monday as the first day of 155the week) as a decimal number (00-53). 156.It Cm \&%w 157is replaced by the weekday (Sunday as the first day of the week) 158as a decimal number (0-6). 159.It Cm \&%X 160is replaced by the locale's appropriate time representation. 161.It Cm \&%x 162is replaced by the locale's appropriate date representation. 163.It Cm \&%Y 164is replaced by the year with century as a decimal number. 165.It Cm \&%y 166is replaced by the year without century as a decimal number (00-99). 167.It Cm \&%Z 168is replaced by the time zone name. 169.It Cm %% 170is replaced by 171.Ql % . 172.El 173.Sh SEE ALSO 174.Xr date 1 , 175.Xr ctime 3 , 176.Xr strptime 3 , 177.Xr printf 1 , 178.Xr printf 3 179.Sh STANDARDS 180The 181.Fn strftime 182function 183conforms to 184.St -ansiC . 185The 186.Ql \&%C , 187.Ql \&%D , 188.Ql \&%e , 189.Ql \&%h , 190.Ql \&%k , 191.Ql \&%l , 192.Ql \&%n , 193.Ql \&%r , 194.Ql \&%R , 195.Ql \&%s . 196.Ql \&%t , 197.Ql \&%T , 198.Ql \&%u , 199and 200.Ql \&%V 201conversion specifications are extensions. 202.Sh BUGS 203There is no conversion specification for the phase of the moon. 204