.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one
.\" 
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\" 
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" References consulted:
.\"     Linux libc source code
.\"     Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\"     386BSD man pages
.\" Modified Sat Jul 24 19:49:27 1993 by Rik Faith (faith@cs.unc.edu)
.\" Modified Fri Apr 26 12:38:55 MET DST 1996 by Martin Schulze (joey@linux.de)
.\" Modified 2001-11-13, aeb
.\"
.\" Japanese Version Copyright (c) 1997 Hiroaki Nagoya
.\"         all rights reserved.
.\" Translated Mon Feb 10 1997 by Hiroaki Nagoya <nagoya@is.titech.ac.jp>
.\" Updated Mon Sep  1 JST 1999 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated Mon Oct 15 JST 2001 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated Thu Dec 13 JST 2001 by Kentaro Shirakata <argrath@ub32.org>
.\" Updated Thu Jan  3 JST 2002 by Kentaro Shirakata <argrath@ub32.org>
.\"
.\"WORD: Coordinated Univarsal Time  
.\"WORD: broken-down time  ̤λ
.TH CTIME 3  2001-11-13 "" "Linux Programmer's Manual"
.SH ̾
asctime, ctime, gmtime, localtime, mktime \- ХʥǡȻ̤λ ASCII Ѵ
.SH 
.nf
.B #include <time.h>
.sp
.BI "char *asctime(const struct tm *" tm );
.br
.BI "char *asctime_r(const struct tm *" tm ", char *" buf );
.sp
.BI "char *ctime(const time_t *" timep );
.br
.BI "char *ctime_r(const time_t *" timep ", char *" buf );
.sp
.BI "struct tm *gmtime(const time_t *" timep );
.br
.BI "struct tm *gmtime_r(const time_t *" timep ", struct tm *" result );
.sp
.BI "struct tm *localtime(const time_t *" timep );
.br
.BI "struct tm *localtime_r(const time_t *" timep ", struct tm *" result );
.sp
.BI "time_t mktime(struct tm *" tm );
.fi
.SH 
ؿ \fBctime()\fP, \fBgmtime()\fP  \fBlocaltime()\fP 
\fItime_t\fP ΥȤ롣
ͤ϶(UTC) 1970 ǯ 1  1  00:00:00
ηвÿȲᤵ롣
.PP
ؿ \fBasctime()\fP  \fBmktime()\fP 
ǯʤɤʬΥ줿̤λȤ롣
.PP
̤λ \fI<time.h>\fP ǰʲΤ褦Ƥ 
\fItm\fP ¤Τݻ롣
.sp
.RS
.nf
.ne 11
.ta 8n 16n 32n
struct tm {
        int     tm_sec;                 /*  */
        int     tm_min;                 /* ʬ */
        int     tm_hour;                /*  */
        int     tm_mday;                /*  */
        int     tm_mon;                 /*  */
        int     tm_year;                /* ǯ */
        int     tm_wday;                /*  */
        int     tm_yday;                /* ǯ̻ */
        int     tm_isdst;               /* ƻ */
};
.ta
.fi
.RE
.PP
\fItm\fP ¤ΤΥСϰʲ̤:
.TP
.I tm_sec
ÿդĤ 0  59 ޤǤ͡
äΤ 61 ޤǤͤϵ롣
.TP
.I tm_min
ʬ0  59 ޤǤ͡
.TP
.I tm_hour
椫̻֡0  23 ޤǤ͡
.TP
.I tm_mday
Ϥᤫ1  31 ޤǤ͡
.TP
.I tm_mon
1̻0  11 ޤǤ͡
.TP
.I tm_year
1900 ǯ̻ǯ
.TP
.I tm_wday
̻()0  6 ޤǤ͡
.TP
.I tm_yday
1  1 ̻0  365 ޤǤ͡
.TP
.I tm_isdst
ƻ֤ͭɤΥե饰
ͤʤвƻ֤ͭˤʤꡢ0 ʤ̵ͤʤФξˤ
̣ʤ
.PP
.BI ctime( t )
ؿ
.BI asctime(localtime( t ))
Ǥ롣
 \fIt\fP 
.sp
.RS
"Wed Jun 30 21:49:08 1993\\n"
.RE
.sp
ȤʸѴ롣
άΤ
`Sun', `Mon', `Tue', `Wed', `Thu', `Fri', `Sat' Ǥ롣
άΤ `Jan', `Feb', `Mar', `Apr', `May', `Jun', `Jul', `Aug',
`Sep', `Oct', `Nov', `Dec' Ǥ롣
֤ͤŪΰ˳ݤ줿ʸؤΥݥ󥿤Ǥ롣ΰ
ǤդաؿθƤӽФˤäƾ񤭤줦롣
ޤδؿѿ \fItzname\fP
.RB ( tzset (3)
) ˸ߤΥॾξꤹ롣
ꥨȥǤǤ \fBctime_r()\fP Ʊͤ
ʸϥ桼Ѱդ26 ʸʾΥΥХåե˳Ǽ롣
\fItzname\fP ꤹɬפϤʤ
.PP
ؿ \fBgmtime()\fP ϥ \fItimep\fP 
(UTC)Ǥ̤λѴ롣
ǯ˼ޤʤ硢NULL ֤
֤ͤŪ˳ݤ줿¤ΤؤƤΤǡ
³ƸƤӽФ뤢դ˴ؤؿˤä
񤭤ǽ롣
\fBgmtime_r()\fP Ʊͤ
ǡϥ桼Ѱդ¤Τ˳Ǽ롣
.PP
ؿ \fBlocaltime()\fP ϥ桼ॾǤλǤѴ롣
δؿ
.BR tzset (3)
ƤӽФΤ褦˿񤤡
ѿ \fItzname\fP ˸ߤΥॾξꤹ롣
ޤ\fItimezone\fP ˶ (UTC) ȥɸȤ
ÿꤷ
ǯΰDzƻ֤ŬѤ \fIdaylight\fP  0 ꤵ롣
֤ͤŪ˳ݤ줿¤ΤؤƤΤǡ
³ƸƤӽФ뤢դ˴ؤؿˤä
񤭤ǽ롣
\fBlocaltime_r()\fP Ʊͤ
ǡϥ桼Ѱդ¤Τ˳Ǽ롣
\fItzname\fP ꤹɬפϤʤ
.PP
ؿ \fBasctime()\fP ̤λ \fItm\fP 
\fBctime()\fP ƱʸѴ롣
֤ͤŪΰ˳ݤ줿ʸؤΥݥ󥿤Ǥ롣ΰ
ǤդաؿθƤӽФˤäƾ񤭤줦롣
ꥨȥǤǤ \fBasctime_r()\fP Ʊͤ
ʸϥ桼Ѱդ26 ʸʾΥΥХåե˳Ǽ롣
.PP
ؿ \fBmktime()\fP (륿ǵҤƤ)̤λ򥫥Ѵ롣
δؿϻǤΤ \fItm_wday\fP  \fItm_yday\fP ̵ͤ뤷
¾λǤ餽Ʒ׻롣
¤ΤǤϰϤˤʤ硢
(Ĥޤꡢ10  40  11  9 ѹ)
ؿ \fBmktime()\fP ƤӽФȡ
ѿ \fItzname\fP ߤΥॾꤵ롣
⤷̤λ򥫥(ÿ)ɽ뤳ȤǤʤäʤС
\fBmktime()\fP  (time_t)(-1) ֤
 \fItm_wday\fP  \fItm_yday\fP ѹʤ
.SH ֤
ƴؿϤ줾Ҥ͡뤤ϥ顼ξ NULL
(\fBmktime()\fP Ǥ \-1)֤
.SH 
.BR acstime() ,
.BR ctime() ,
.BR gmtime() ,
.B localtime()
 4 ĤδؿŪǡؤΥݥ󥿤֤ΤǡåɥդǤϤʤ
δؿΥåɥǤǤ
.BR acstime_r() ,
.BR ctime_r() ,
.BR gmtime_r() ,
.B localtime_r()
SUSv2 ǵꤵ졢libc 5.2.5 ʹߤѤǤ롣
.LP
glibc Ǥϡ
.I <time.h>
󥯥롼ɤ _BSD_SOURCE ȡ
struct tm ˰ʲΥեɤɲä롣
.sp
.RS
.nf
long tm_gmtoff;           /* Seconds east of UTC */
const char *tm_tm_zone;   /* Timezone abbreviation */
.fi
.RE
.sp
 BSD ĥǤꡢ4.3BSD-Reno 鸽줿
.SH 
SVID 3, POSIX, BSD 4.3, ISO 9899
.SH Ϣ
.BR date (1),
.BR gettimeofday (2),
.BR newctime (3),
.BR time (2),
.BR utime (2),
.BR clock (3),
.BR difftime (3),
.BR strftime (3),
.BR strptime (3),
.BR tzset (3)