DIFFTIME(3)		   Linux Programmers Manual		  DIFFTIME(3)



NAME
       difftime - calculate time difference

SYNOPSIS
       #include 

       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
       SVr4, 4.3BSD, C89, C99.

NOTES
       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 doesnt work directly.

SEE ALSO
       date(1), gettimeofday(2), time(2), ctime(3), gmtime(3), localtime(3)

COLOPHON
       This page is part of release 3.05 of the Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.



GNU				  2002-02-28			   DIFFTIME(3)