time_t(3) Linux Programmer's Manual time_t(3) NAME time_t - type representing time SYNOPSIS #include <time.h> typedef ... time_t; DESCRIPTION time_t is an arithmetic type capable of representing time. In POSIX, time_t is defined as counting non-leap seconds since the Epoch (1970-01-01T00:00:00 UTC). Conversions Use localtime(3), gmtime(3) and strftime(3) to convert time_t values to more manageable form. Use mktime(3) to convert back to time_t. NOTES On many platforms time_t is a signed 32-bit integer, counting seconds since 1970. On such platforms it will overflow in AD 2038. The POSIX definition as a count of non-leap-seconds since the Epoch means that leap seconds cannot be represented in time_t, and that sub- tracting two time_t values will not count any leap seconds that occur between them; i.e. it will not give the actual elapsed time. CONFORMING TO ISO/IEC 9899, IEEE Std 1003.1 SEE ALSO time(2), localtime(3), gmtime(3), mktime(3), difftime(3) 2005-02-03 time_t(3)