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'\" t
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH difftime 3 2025-05-17 "Linux man-pages (unreleased)"
.SH NAME
difftime \- calculate time difference
.SH LIBRARY
Standard C library
.RI ( libc ,\~ \-lc )
.SH SYNOPSIS
.nf
.B #include <time.h>
.P
.BI "double difftime(time_t " time1 ", time_t " time0 );
.fi
.SH DESCRIPTION
The
.BR difftime ()
function returns the number of seconds elapsed
between time
.I time1
and time
.IR time0 ,
represented as a
.IR double .
Each time is a count of seconds.
.P
.I difftime(b,\~a)
acts like
.I (b\-a)
except that the result does not overflow and is rounded to
.IR double .
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface Attribute Value
T{
.na
.nh
.BR difftime ()
T} Thread safety MT-Safe
.TE
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
POSIX.1-2001, C89, SVr4, 4.3BSD.
.SH SEE ALSO
.BR date (1),
.BR gettimeofday (2),
.BR time (2),
.BR ctime (3),
.BR gmtime (3),
.BR localtime (3)
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