http://www.cplusplus.com/reference/clibrary/ctime/difftime/ function difftime double difftime ( time_t time2, time_t time1 ); Return difference between two times Calculates the difference in seconds between time1 and time2. Parameters time2 time_t object representing the latter of the two times. time1 time_t object representing the earlier of the two times. Return Value The difference in seconds..