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).
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 doesn't work directly.
SEE ALSO¶
date(1),
gettimeofday(2),
time(2),
ctime(3),
gmtime(3),
localtime(3)
COLOPHON¶
This page is part of release 3.44 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/.
