difftime man page


This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

difftime — compute the difference between two calendar time values


#include <time.h>

double difftime(time_t time1, time_t time0);


The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1‐2008 defers to the ISO C standard.

The difftime() function shall compute the difference between two calendar times (as returned by time()): time1- time0.

Return Value

The difftime() function shall return the difference expressed in seconds as a type double.


No errors are defined.

The following sections are informative.

See Also

asctime(), clock(), ctime(), gmtime(), localtime(), mktime(), strftime(), strptime(), time(), utime()

The Base Definitions volume of POSIX.1‐2008, <time.h>


2013 IEEE/The Open Group POSIX Programmer's Manual