VMS Help CC, Run-time functions, localtime, localtime_r  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Converts a time (expressed as the number of seconds elapsed since
  00:00:00, January 1, 1970) into hours, minutes, seconds, and so on.
  This function is nonreentrant.

  localtime_r puts the result into a user-specified tm structure.

  localtime stores the result into thread-specific static memory
  allocated by the Compaq C RTL, and which is overwritten by
  subsequent calls to localtime; you must make a copy if you want to
  save it.

  Syntax:

       #include <time.h>

       struct tm *localtime(const time_t *timer);

       struct tm *localtime_r(const time_t *timer, struct tm
       *result); [posix1]