difftime(3) - phpMan

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).
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 3.53 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                               2012-12-22                       DIFFTIME(3)