VMS Help CC, Language topics, Predefined Macros, DATE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  The __DATE__ macro evaluates to a string specifying the date on
  which the compilation started.  The string presents the date in the
  form "Mmm dd yyyy" The names of the months are those generated by
  the asctime library function.  The first d is a space if dd is less
  than 10.

  Example:

       printf("%s",__DATE__);