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

difftime - calculate time difference

#include <time.h>

double difftime(time_t time1, time_t time0);

The difftime() function returns the number of seconds elapsed between time time1 and time time0, represented as a double. The two times are specified in calendar time, which represents the time elapsed since the Epoch (00:00:00 on January 1, 1970, Coordinated Universal Time (UTC)).

SVr4, 4.3BSD, C89, C99

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.

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

This page is part of release 2.77 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/.

2002-02-28 GNU

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