BUG #2366: Timestamptz data type is inaccurate

The following bug has been logged online:

Bug reference:      2366
Logged by:          Christian Holtje
Email address:      christian.holtje@timesys.com
PostgreSQL version: 7.4.8
Operating system:   Ubuntu 5.10
Description:        Timestamptz data type is inaccurate
Details:

I don't know what's going on, but basically, for some dates timestamptz is
loosing parts of the date/time (like the timezone, etc.)

db=# select '2076-03-30 19:57:05-05'::timestamptz;
     timestamptz
---------------------
 2076-03-31 00:57:05
(1 row)

db=# select '2037-03-30 19:57:05-05'::timestamptz;
      timestamptz
------------------------
 2037-03-30 20:57:05-04
(1 row)

db=# select '2006-03-30 19:57:05-05'::timestamptz + '100 years'::interval;
      ?column?
---------------------
 2106-03-30 19:57:05
(1 row)

Note that the hours, minutes or timezone aren't correct.  I tried the last
one to make sure it's not due to the parser.

Thanks for your help.