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# gmtime

From cppreference.com
< c‎ | chrono

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).

### [edit] Parameters

time | - | pointer to a time_t object to convert

### [edit] Return value

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

### [edit] 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.

### [edit] Example

Run this code

    #include <stdio.h>
    #include <time.h>
    #include <stdlib.h>

    int main(void)
    {
        time_t t = time(NULL);
        struct tm *tmptr = gmtime(&t);
        if (tmptr == NULL)
        {
           fprintf(stderr,"gmtime() failed in file %s at line # %d\n", __FILE__,__LINE__-3);
           exit(EXIT_FAILURE);
        }

        printf("UTC:   %s", asctime(tmptr));
        printf("local: %s", asctime(localtime(&t)));

        return EXIT_SUCCESS;
    }

Output:

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

### [edit] See also

localtime | converts time since epoch to calendar time expressed as local time (function) [edit]
C++ documentation for gmtime

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