Forcing postgres to reload current time zone.

Hello,

I'm writing an application that issues "SELECT current_timestamp" from
postgres on a regular basis to get the time. However, the user may
change the system's time zone and postgres does not seem to reflect this
change unless I restart the database daemon. I cannot have all of my
program threads issue a SET TIME ZONE query, and was hoping there is a
query I could issue that would globally update the time zone for all
currently running postgres sessions, or a more gentle way to force
postgres to reload its time zone information without completely
restarting the daemon. Any advice?

I've done quite a bit of searching for this answer and I'm not coming up
with anything useful. I'm running postgres on RedHat Linux 9.

Many thanks,

trena