.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved. The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\" @(#)ctime.3 6.3 (Berkeley) %G%
ctime, localtime, gmtime, asctime, timezone \- convert date and time to ASCII
.B struct tm *localtime(clock)
.B struct tm *gmtime(clock)
.B char *timezone(zone, dst)
converts a time pointed to by
and returns a pointer to a
All the fields have constant width.
Sun Sep 16 01:03:52 1973\\n\\0
return pointers to structures containing
corrects for the time zone and possible daylight savings time;
converts directly to GMT, which is the time UNIX uses.
converts a broken-down time to ASCII and returns a pointer
to a 26-character string.
The structure declaration from the include file is:
.nr .0 .8i+\w'int tm_isdst'u
.ta .5i \n(.0u \n(.0u+\w'/* 0-000'u+1n
int tm_sec; /* 0-59 seconds */
int tm_min; /* 0-59 minutes */
int tm_hour; /* 0-23 hour */
int tm_mday; /* 1-31 day of month */
int tm_mon; /* 0-11 month */
int tm_year; /* 0- year \- 1900 */
int tm_wday; /* 0-6 day of week (Sunday = 0) */
int tm_yday; /* 0-365 day of year */
int tm_isdst; /* flag: daylight savings time in effect */
When local time is called for,
the program consults the system to determine the time zone and
whether the U.S.A., Australian, Eastern European, Middle European,
or Western European daylight saving time adjustment is appropriate.
The program knows about various peculiarities in time conversion
over the past 10-20 years; if necessary, this understanding can
returns the name of the time zone associated with its first argument,
which is measured in minutes westward from Greenwich.
If the second argument is 0, the standard name is used,
otherwise the Daylight Saving version.
If the required name does not appear in a table
the difference from GMT is produced; e.g.
.I timezone(-(60*4+30), 0)
is appropriate because it is 4:30 ahead of GMT
The return values point to static data
whose content is overwritten by each call.