localtime64() — Convert Time

Format 

#include <time.h>
struct tm *localtime64(const time64_t *timeval);

Language Level: ILE C Extension

Threadsafe: No. Use localtime64_r() instead.

Locale Sensitive: The behavior of this function might be affected by the LC_TOD category of the current locale.

Description

The localtime64() function converts a time value, in seconds, to a structure of type tm.

The localtime64() function takes a timeval assumed to be Universal Coordinate Time (UTC) and converts it to job locale time. For this conversion, localtime64() checks the current locale setting for local time zone and daylight saving time (DST). If these values are not set in the current locale, localtime64() gets the local time zone and daylight saving time (DST) settings from the current job. Once converted, the time is returned in a structure of type tm. If the DST is set in the locale but the time zone information is not, the DST information in the locale is ignored.

The time value is usually obtained by a call to the time64() function.

Notes:
  1. The gmtime64() and localtime64() functions might use a common, statically allocated buffer for the conversion. Each call to one of these functions might alter the result of the previous call. The asctime_r(), ctime64_r(), gmtime64_r() and localtime64_r() functions do not use a common, statically allocated buffer. These functions can be used in place of the asctime(), ctime64(), gmtime64(), and localtime64() functions if thread safety is desired.
  2. Calendar time is the number of seconds that have elapsed since EPOCH, which is 00:00:00, January 1, 1970 Universal Coordinate Time (UTC).
  3. The supported date and time range for this function is 01/01/0001 00:00: 00 through 12/31/9999 23: 59: 59.

Return Value

The localtime64() function returns a pointer to the structure result. If the given timeval is out of range, a NULL pointer is returned and errno is set to EOVERFLOW.

Example that uses localtime64()

This example queries the system clock and displays the local time. 

#include <stdio.h>
#include <time.h>
 
int main(void)
{
   struct tm *newtime;
   time64_t ltime;
 
   ltime = time64(&ltime);
   newtime = localtime64(&ltime);
   printf("The date and time is %s", asctime(newtime));
}
 
/**************  If the local time is 3 p.m. February 15, 2008, **********
*************************  the output should be: *********************
 
The date and time is Fri Feb 15 15:00:00 2008
*/

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