Timezone from PG8 to PG9

Hello we were upgrading a test system from PG8.3.6 to PG 9.3 and it appears
as though the timezone is not set on the new PG9.3. I should say that we
never did set the timezone for PG8, but somehow the PG server knew the
'localtime' of the system:

show timezone;
TimeZone
------------
US/Eastern
(1 row)

However, after upgrading to PG9:
show timezone;
TimeZone
----------
GMT
(1 row)

We saw the same for US/Pacific zone as well.

We do set /etc/localtime for the local timezone of the box. We can
configure this in the postgresql.conf file. It does appear as though PG9
server reads /etc/localtime on startup, but it is not set. Just wondering
if it was working previously, because of some side effect, or if this has
changed some other way. I believe the environment did not change between
PG8 and PG9 at least as far as I can determine.

The Server is CentOS 6.

Deron