Time stamp(s)

[Paul Eggert]

   From: "Olson, Arthur David" <OLSONA at dc37a.nci.nih.gov>
   Date: Fri, 31 Oct 1997 08:30:14 -0500

   my guess is that the thing to do is put at the start of the file a
   count of the number of bytes worth of stamp that appear, then put
   the stamp information itself at the end of the file.

How would this work with the Unix `file' command?
On Solaris 2.6, at least, that command looks only at the first 512 bytes.


   The stamp might be automatically generated as a function of
	   the maximum "until" time appearing on a "Zone" line for the zone
   in question
   and
	   the maximum "from" and "to" years appearing on a "Rule" line for
   the zone in question.

I'm not sure how well this would work in practice, even for future
times.  E.g. suppose Asia/Tehran switched from its current system
(based on the Persian calendar) to some other set of rules that could
be expressed in two lines rather than two lines per year.  Then the
UNTIL time wouldn't change, and the FROM and TO years would shrink, so
it'd look like we had an older version.

And of course I'd like to have past times updated correctly, as well.

Why not use a timestamp as a comment in the first line?
E.g. change

# @(#)asia      7.30

to something like this:

# @(#)asia      7.30 1997-11-01 10:20:30

I think SCCS will do that for you.