### 8.4 `difftime`—subtract two times

Synopsis

         #include <time.h>
         double difftime(time_t tim1, time_t tim2);

Description
Subtracts the two times in the arguments: `tim1`-` tim2'.

Returns
The difference (in seconds) between tim2 and tim1, as a `double`.

Portability
ANSI C requires `difftime`, and defines its result to be in seconds in all implementations.

`difftime` requires no supporting OS subroutines.