Converts a time value to a structure.
#include <time.h>
struct tm *gmtime( const time_t *time );
| timer | Pointer to stored time |
The gmtime function converts the timer value to a structure. The timer argument represents the seconds elapsed since midnight (00:00:00), December 31, 1899, Universal Coordinated Time. This value is usually obtained from a call to the time function.
The gmtime function breaks down the timer value and stores it in a structure of type tm, defined in TIME.H. The structure result reflects Universal Coordinated Time, not local time.
The fields of the structure type tm store the following values, each of which is an int:
| Field | Value Stored |
| tm_sec | Seconds |
| tm_min | Minutes |
| tm_hour | Hours (0–24) |
| tm_mday | Day of month (1–31) |
| tm_mon | Month (0–11; January = 0) |
| tm_year | Year (current year minus 1900) |
| tm_wday | Day of week (0–6; Sunday = 0) |
| tm_yday | Day of year (0–365; January 1 = 0) |
| tm_isdst | Always 0 for gmtime |
The gmtime, mktime, and localtime functions use a single statically allocated structure to hold the result. Each call to one of these routines destroys the result of any previous call.
If timer represents a date before midnight, December 31, 1899, gmtime returns NULL.
The gmtime function returns a pointer to the structure result. There is no error return.
Standards:ANSI, UNIX
16-Bit:DOS, QWIN, WIN, WIN DLL
32-Bit:DOS32X
asctime, ctime, _ftime, localtime, time
/* GMTIME.C: This program uses gmtime to convert a long-integer
* representation of Universal Coordinated Time to a structure named newtime,
* then uses asctime to convert this structure to an output string.
*/
#include <time.h>
#include <stdio.h>
void main( void )
{
struct tm *newtime;
long ltime;
time( <ime );
/* Obtain Universal Coordinated Time: */
newtime = gmtime( <ime );
printf( "Universal Coordinated Time is %s\n", asctime( newtime ) );
}
Universal Coordinated Time is Wed Jun 16 16:37:53 1999