opensolaris man page for difftime

difftime(3C)						   Standard C Library Functions 					      difftime(3C)

NAME
       difftime - computes the difference between two calendar times

SYNOPSIS
       #include <time.h>

       double difftime(time_t time1, time_t time0);

DESCRIPTION
       The difftime() function computes the difference between two  calendar times.

RETURN VALUES
       The difftime() functions returns the difference (time1-time0) expressed in seconds as a double.

USAGE
       The difftime() function is provided because there are no general arithmetic properties defined for type time_t.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       ctime(3C), attributes(5), standards(5)

SunOS 5.11							    24 Jul 2002 						      difftime(3C)