Linux man pages : time (2)
TIME(2) Linux Programmer's Manual TIME(2)
time - get time in seconds
time_t time(time_t *t);
time returns the time since the Epoch (00:00:00 UTC, January 1, 1970),
measured in seconds.
If t is non-NULL, the return value is also stored in the memory pointed
to by t.
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.
EFAULT t points outside your accessible address space.
POSIX.1 defines seconds since the Epoch as a value to be interpreted as
the number of seconds between a specified time and the Epoch, according
to a formula for conversion from UTC equivalent to conversion on the na
Linux 2.0.30 1997-09-09 TIME(2)