tracking change dates for substack

[Dr. Hawkins]

Is there a practical way to automatically track the change dates for
substacks?

I'm about to end up with something like 100 of them (one for each judicial
district)

At the moment, I have routines that step through all of my cards every time
I bump the revision, but it would be nice to be able to skip stacks.

I guess I'm looking for something like a last changed date on a directory,
but for substacks instead.

-- 
Dr. Richard E. Hawkins, Esq.
(702) 508-8462