If the process has appropriate privilege, the stime() function shall set the system's idea of the time and date. Time, referenced by t, is measured in seconds from the epoch (defined in POSIX 1003.1-2008 (ISO/IEC 9945-2009) as 00:00:00 UTC January 1, 1970).
On success, stime() shall return
Otherwise, stime() shall return
errno shall be set to indicate the error.