The following bug has been logged online:
Bug reference:      4539
Logged by:          Stuart Green
Email address:      stuart@greenfam.com
PostgreSQL version: 8.2.11
Operating system:   Centos 5
Description:        to_char(to_timestamp('...','....')) returns the wrong
result
Details:
The query
select to_char(to_timestamp('2008-11-14 16:00:00','YYYY-MM-DD
HH24:MM:SS'),'day');
is returning monday as the day in all the dbase version I Have test, 8.2.11,
8.2.10, and 8.1.11
The query
select to_char(to_timestamp('2008-11-14','YYYY-MM-DD'),'day');
returns friday, which is correct, if you replace to_timestamp with to_date
it returns friday which is correct.
Specify the 24 hour clock or not in the timestamp query doesn't make a
difference in the result, it still returns monday, when it should be friday.