TIME(2) Linux Programmer's Manual TIME(2)
NAME
time - get time in seconds
SYNOPSIS
#include <time.h>
time_t time(time_t *t);
DESCRIPTION
time() returns the time as the number of seconds since the Epoch,
1970-01-01 00:00:00 +0000 (UTC).
If t is non-NULL, the return value is also stored in the memory pointed
to by t.
RETURN VALUE
On success, the value of time in seconds since the Epoch is returned.
On error, ((time_t) -1) is returned, and errno is set appropriately.
ERRORS
EFAULT t points outside your accessible address space.
CONFORMING TO
SVr4, 4.3BSD, C89, C99, POSIX.1-2001. POSIX does not specify any error
conditions.
NOTES
POSIX.1 defines seconds since the Epoch using a formula that approxi-
mates the number of seconds between a specified time and the Epoch.
This formula takes account of the facts that all years that are evenly
divisible by 4 are leap years, but years that are evenly divisible by
100 are not leap years unless they are also evenly divisible by 400, in
which case they are leap years. This value is not the same as the
actual number of seconds between the time and the Epoch, because of
leap seconds and because system clocks are not required to be synchro-
nized to a standard reference. The intention is that the interpreta-
tion of seconds since the Epoch values be consistent; see POSIX.1-2008
Rationale A.4.15 for further rationale.
SEE ALSO
date(1), gettimeofday(2), ctime(3), ftime(3), time(7)
COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2011-09-09 TIME(2)