How to obtain file date rather than current date

[Marshall D. Abrams]

I am using troff with the ms macros to produce hardcopy of a file
which is getting many updates.  When I print it I am using the DA
directive to get the date printed on the hardcopy.  But this is the
date printed.  I would much rather have the date that the file
was last revised.  Any suggestion on how to do this would be
appreciated.

Please respond directly, as I am not on the list.

Thank you.

Sincerely,

 - Marshall D. Abrams, phone: (703) 883-6938
   The MITRE Corporation, 7525 Colshire Drive
   Mail Stop W458, Mc Lean, VA   22102