difftime(3) 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

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
difftime() Thread safetyMT-Safe

CONFORMING TO

POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.

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.

COLOPHON

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