+.\" Copyright (c) 1989, 1991 The Regents of the University of California.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" the American National Standards Committee X3, on Information
+.\" Processing Systems.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\" notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\" notice, this list of conditions and the following disclaimer in the
+.\" documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\" must display the following acknowledgement:
+.\" This product includes software developed by the University of
+.\" California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\" may be used to endorse or promote products derived from this software
+.\" without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\" @(#)strftime.3 5.12 (Berkeley) 6/29/91
+.\"
+.Dd June 29, 1991
+.Dt STRFTIME 3
+.Os
+.Sh NAME
+.Nm strftime
+.Nd format date and time
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <time.h>
+.Fd #include <string.h>
+.Ft size_t
+.Fn strftime "char *buf" "size_t maxsize" "const char *format" "const struct tm *timeptr"
+.Sh DESCRIPTION
+The
+.Fn strftime
+function formats the information from
+.Fa timeptr
+into the buffer
+.Fa buf
+according to the string pointed to by
+.Fa format .
+.Pp
+The
+.Fa 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
+.Dq Ql %
+and one other character.
+.Pp
+No more than
+.Fa maxsize
+characters will be placed into the array.
+If the total number of resulting characters, including the terminating
+null character, is not more than
+.Fa maxsize ,
+.Fn 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.
+.Bl -tag -width "xxxx"
+.It Cm \&%A
+is replaced by the full weekday name.
+.It Cm %a
+is replaced by the abbreviated weekday name, where the abbreviation
+is the first three characters.
+.It Cm \&%B
+is replaced by the full month name.
+.It Cm %b or %h
+is replaced by the abbreviated month name, where the abbreviation is
+the first three characters.
+.It Cm \&%C
+is equivalent to
+.Dq Li %a %b %e %H:%M:%S %Y
+(the format produced by
+.Xr asctime 3 .
+.It Cm %c
+is equivalent to
+.Dq Li %m/%d/%y .
+.It Cm \&%D
+is replaced by the date in the format
+.Dq Ql mm/dd/yy .
+.It Cm %d
+is replaced by the day of the month as a decimal number (01-31).
+.It Cm %e
+is replaced by the day of month as a decimal number (1-31); single
+digits are preceded by a blank.
+.It Cm \&%H
+is replaced by the hour (24-hour clock) as a decimal number (00-23).
+.It Cm \&%I
+is replaced by the hour (12-hour clock) as a decimal number (01-12).
+.It Cm %j
+is replaced by the day of the year as a decimal number (001-366).
+.It Cm %k
+is replaced by the hour (24-hour clock) as a decimal number (0-23);
+single digits are preceded by a blank.
+.It Cm %l
+is replaced by the hour (12-hour clock) as a decimal number (1-12);
+single digits are preceded by a blank.
+.It Cm \&%M
+is replaced by the minute as a decimal number (00-59).
+.It Cm %m
+is replaced by the month as a decimal number (01-12).
+.It Cm %n
+is replaced by a newline.
+.It Cm %p
+is replaced by either
+.Dq Tn AM
+or
+.Dq Tn PM
+as appropriate.
+.It Cm \&%R
+is equivalent to
+.Dq Li %H:%M
+.It Cm %r
+is equivalent to
+.Dq Li %I:%M:%S %p .
+.It Cm %t
+is replaced by a tab.
+.It Cm \&%S
+is replaced by the second as a decimal number (00-60).
+.It Cm %s
+is replaced by the number of seconds since the Epoch, UCT (see
+.Xr mktime 3 ) .
+.It Cm \&%T No or Cm \&%X
+is equivalent to
+.Dq Li %H:%M:%S .
+.It Cm \&%U
+is replaced by the week number of the year (Sunday as the first day of
+the week) as a decimal number (00-53).
+.It Cm \&%W
+is replaced by the week number of the year (Monday as the first day of
+the week) as a decimal number (00-53).
+.It Cm %w
+is replaced by the weekday (Sunday as the first day of the week)
+as a decimal number (0-6).
+.It Cm %x
+is equivalent to
+.Dq Li %m/%d/%y %H:%M:%S .
+.It Cm \&%Y
+is replaced by the year with century as a decimal number.
+.It Cm %y
+is replaced by the year without century as a decimal number (00-99).
+.It Cm \&%Z
+is replaced by the time zone name.
+.It Cm %%
+is replaced by
+.Ql % .
+.El
+.Sh SEE ALSO
+.Xr date 1 ,
+.Xr ctime 3 ,
+.Xr printf 1 ,
+.Xr printf 3
+.Sh STANDARDS
+The
+.Fn strftime
+function
+conforms to
+.St -ansiC .
+The
+.Ql %s
+conversion specification is an extension.
+.Sh BUGS
+There is no conversion specification for the phase of the moon.
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