PG is in different timezone than the OS

Hi all,

I am not sure if this is the correct list to post this issue. Please let me
know if there is a more suitable one.

Argentina's government has recently decreted a timezone change for the
summer (daylight's savings) where local time zone changes from GMT-3 to
GMT-2. The Argentinean Summer Timezone is named "ARST".

My first problem is that Postgres still hangs with GMT-3 while OS is at
GMT-2

*OS date*
# date -R ; date
Wed, 02 Jan 2008 16:07:36 -0200
Wed Jan 2 16:07:36 ARST 2008

*Postgres*
radius=# select now()::timestamp with time zone;
now
-------------------------------
2008-01-02 15:07:59.435233-03
(1 row)

As you can see PG is at GMT-03. Restart has been done to no effect.
Postgres.conf settings are:

# - Locale and Formatting -

#datestyle = 'iso, mdy'
#timezone = unknown # actually, defaults to TZ
# environment setting
#australian_timezones = off
#extra_float_digits = 0 # min -15, max 2
#client_encoding = sql_ascii # actually, defaults to database
# encoding

I have also tried with:
timezone='America/Argentina/Cordoba'

How do I tell postgres that it is located in Argentina/Cordoba or GMT-02? Is
there a way to have it relay to the OS?

My second problem is that Postgres doesn't recognize the timezone ARST.

pg=# select '01:13:16.426 ARST Wed Jan 2 2008'::timestamp with time zone;
ERROR: invalid input syntax for type timestamp with time zone:
"01:13:16.426 ARST Wed Jan 2 2008"

Whereas with the previous ART timezone it did well:

pg=# select '01:13:16.426 ART Wed Jan 2 2008'::timestamp with time zone;
timestamptz
----------------------------
2008-01-02 01:13:16.426-03
(1 row)

I'm lost here. ARST isn't new. It has been used in former years.
Any help would be greatly appreciated.

Regards,
Fernando