Re: daylight savings patches needed?

We have a 7.4.6 cluster which has been running on an HP B.11.00
box for quite sometime.  The IT group applied daylight savings
patches to the OS, but the cluster is still showing the
incorrect timezone:

$ psql -c "select now()"
              now
-------------------------------
 2007-03-12 13:46:11.369583-05

$ date
Mon Mar 12 14:46:18 EDT 2007

It appears that newly initialized 7.4.6 clusters get the proper
timezone.  I didn't see anything in the FAQ about restarting.

Does this mean that we need to restart these clusters in order to
get the timezone updates from the OS?  Are they cached in the
postmaster?

TIA.
Ed