DIFFTIME(E)         Linux Programmer's Manual         DIFFTIME(E)



NAME
       difftime - calculate time difference

SYNOPSIS
       #include <time.h>

       double difftime(time_t time1, time_t time0);

DESCRIPTION
       The  difftime()  function  returns  the  number of seconds
       elapsed between time time1 and time time0, represented  as
       a  double.   The two times are specified in calendar time,
       which  represents  the  time  elapsed  since   the   Epoch
       (00:00:00  on  January 1, 1970, Coordinated Universal Time
       (UTC)).

CONFORMING TO
       SVID 3, BSD 4.3, ISO 9899

NOTES
       This function is required by ANSI C.  On a  POSIX  system,
       time_t is an arithmetic type, and one could just define

              #define difftime(t1,t0) (double)(t1 - t0)

       when  the  possible  overflow  in the subtraction is not a
       concern.  On other systems, the data type time_t might use
       some   other   encoding  where  subtraction  doesn't  work
       directly.

CONFORMING TO
       SVID 3, BSD 4.3, ISO 9899

SEE ALSO
       date(e), gettimeofday(y),  time(e),  ctime(e),  gmtime(e),
       localtime(e)



GNU                         2002-02-28                DIFFTIME(E)