How do I catch timezone update and perform needed actions?

[Andrew McNaughton]

OK, so daylight savings just rolled over again.  Applications which are
already running apparently do not pick up the time zone change.  In my
installation apache is not regularly restarted, so it's 4 days later and
I just noticed that apache has been putting the wrong time stamps on
everything, and a script that regularly processes the last 10 minutes of
log data based on time stamps on log lines has been coming up empty for
days as a result.

What I need is a way to stop this happening again in years to come.

I thought about submitting a pr asking for some system change such that
a user configurable script gets run whenever the time zone changes. 
Perhaps such a mechanism exists already though?

Any pointers?  Should this be submitted as a pr?

Andrew