difftime, difftime64 - Calculate time difference

Definition	#include <time.h> double difftime(time_t time2, time_t time1); double difftime64(time64_t time2, time64_t time1); difftime and difftime64 calculate the difference between time2 and time1. The time values must be of type time_t or time64_t. Such time values are supplied for instance by the mktime and time or mktime64 and time64 functions.
Return val.	Time difference in seconds in floating point representation.
See also	time, time64, mktime, mktime64, ftime, ftime64, localtime, localtime64, asctime, gmtime, gmtime64