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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
approximates 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 synchronized to a standard reference. The intention is
that the interpretation 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
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