timegm(3) Library Functions Manual timegm(3) timegm, timelocal - gmtime localtime LIBRARY Standard C library (libc, -lc) #include [[deprecated]] time_t timelocal(struct tm *tm); time_t timegm(struct tm *tm); glibc (. feature_test_macros(7)): timelocal(), timegm(): glibc 2.19: _DEFAULT_SOURCE glibc 2.19 : _BSD_SOURCE || _SVID_SOURCE timelocal() timegm() localtime(3) gmtime(3). ( 1970-01-01 00:00:00 +0000, UTC). , timelocal() , timegm() (Coordinated Universal Time, UTC). On success, these functions return the calendar time (seconds since the Epoch), expressed as a value of type time_t. On error, they return the value (time_t) -1 and set errno to indicate the error. EOVERFLOW . attributes(7). +----------------------------+----------------------------------------------------------+--------------------------+ | | | | +----------------------------+----------------------------------------------------------+--------------------------+ |timelocal(), timegm() | | MT-Safe env locale | +----------------------------+----------------------------------------------------------+--------------------------+ BSD. GNU, BSD. timelocal() POSIX mktime(3). - . . gmtime(3), localtime(3), mktime(3), tzset(3) Azamat Hackimov , Dmitry Bolkhovskikh , Yuri Kozlov ; GNU 3 , . . , , . Linux man-pages 6.06 31 2023 . timegm(3)