Go forward to gmtime
Go backward to ctime
Go up to Timefns
Go to the top op libc

`difftime'--subtract two times

     #include <time.h>
     double difftime(time_t TIM1, time_t TIM2);
Subtracts the two times in the arguments: ``TIM1 - TIM2''.
The difference (in seconds) between TIM2 and TIM1, as a `double'.
ANSI C requires `difftime', and defines its result to be in seconds in
all implementations.
   `difftime' requires no supporting OS subroutines.