gmtime

 

C

Compiler support

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (C11)

Technical Specifications

Symbol index

 

Date and time utilities

Functions

Time manipulation

difftime

time

clock

timespec_get (C11)

timespec_getres (C23)

Format conversions

asctimeasctime_s (deprecated in C23)(C11)

ctimectime_s (deprecated in C23)(C11)

strftime

wcsftime (C95)

gmtimegmtime_rgmtime_s (C23)(C11)

localtimelocaltime_rlocaltime_s (C23)(C11)

mktime

Constants

CLOCKS_PER_SEC

Types

tm

time_t

clock_t

timespec (C11)

 

Defined in header <time.h>
tm* gmtime( const time_t* time );

Converts given time since epoch as time_t value into calendar time, expressed in Coordinated Universal Time (UTC).

Parameters

time

-

pointer to a time_t object to convert

Return value

pointer to a static internal tm object on success, or NULL otherwise. The structure may shared between gmtime, localtime, and ctime and may be overwritten on each invocation.

Notes

This function may not be thread-safe.

POSIX requires that this function sets errno to EOVERFLOW if it fails because the argument is too large.

Example

Run this code

#include <stdio.h>
#include <time.h>
 
int main()
{
    time_t t = time(NULL);
    printf("UTC:   %s", asctime(gmtime(&t)));
    printf("local: %s", asctime(localtime(&t)));
 
    return 0;
}

Output:

UTC:   Wed Oct  9 10:37:39 2013
local: Wed Oct  9 17:37:39 2013

See also

localtimelocaltime_rlocaltime_s (C23)(C11)	converts time since epoch to calendar time expressed as local time (function)
C++ documentation for gmtime