How to signal a time zone change?

[Peter Steele]

>You need to signal your app in some way.. Assuming you have source for
the app then you can monitor /etc/localtime (or /etc) for change with
kevent.

Signaling our C apps aren't the problem. We have an IPC framework in
place and we can easily tell the C apps when the user has changed the
time zone via the GUI. The problem is I can't figure out what C calls
are needed to instantiate the time zone change. Based on the
documentation, I would think that tzset() would do the trick once
/etc/localtime has been updated by the Java app, but this does not work.
The only way I've discovered that works is to restart our C apps and we
want to avoid that.