#define _GNU_SOURCE #include "time_impl.h" #include time_t timegm(struct tm *tm) { struct tm new; long long t = __tm_to_secs(tm); if (__secs_to_tm(t, &new) < 0) { errno = EOVERFLOW; return -1; } *tm = new; tm->tm_isdst = 0; tm->__tm_gmtoff = 0; tm->__tm_zone = __utc; return t; }