DIFFTIME(3)                         Linux Programmer's Manual                         DIFFTIME(3)



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.  Each of the times is specified in  calendar  time,  which
       means  its  value is a measurement (in seconds) relative to the Epoch, 1970-01-01 00:00:00
       +0000 (UTC).

ATTRIBUTES
   Multithreading (see pthreads(7))
       The difftime() function is thread-safe.

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.

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

COLOPHON
       This page is part of release 3.74 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at http://www.kernel.org/doc/man-pages/.



GNU                                         2013-10-28                                DIFFTIME(3)