TIME(3) Library Functions Manual TIME(3) NAME time – get time of day LIBRARY Standard C Library (libc, -lc) SYNOPSIS #include <time.h> time_t time(time_t *tloc); DESCRIPTION The time() function returns the value of time in seconds since 0 hours, 0 minutes, 0 seconds, January 1, 1970, Coordinated Universal Time, without including leap seconds. If an error occurs, time() returns the value (time_t)-1. The return value is also stored in *tloc, provided that tloc is non-null. ERRORS The time() function may fail for any of the reasons described in gettimeofday(2). SEE ALSO gettimeofday(2), ctime(3) STANDARDS The time function conforms to IEEE Std 1003.1-2001 (“POSIX.1”). HISTORY A time() function appeared in Version 6 AT&T UNIX. BUGS Neither ISO/IEC 9899:1999 (“ISO C99”) nor IEEE Std 1003.1-2001 (“POSIX.1”) requires time() to set errno on failure; thus, it is impossible for an application to distinguish the valid time value -1 (representing the last UTC second of 1969) from the error return value. Systems conforming to earlier versions of the C and POSIX standards (including older versions of FreeBSD) did not set *tloc in the error case. macOS 15.2 July 18, 2003 macOS 15.2