Timestamp + Interval time zone issues

[Mike Ginsburg]

Jon Radel wrote:
> On 7/28/10 2:28 PM, Mike Ginsburg wrote:
>>
>> So I have pg 8.4.3 installed, with a database set to EST5EDT time zone.
>>
>> When I run "SELECT NOW()" I get
>> 07/28/2010 14:27:07.767286 EDT
>>
>> showing that the timezone is properly set up.
>>
>> When I then try to add an interval to a statically entered time 
>> stamp, it gets all strange:
>> SELECT '01/03/2011 16:00:00-04'::timestamp with time zone + '-1 
>> hour'::interval;
>>        ?column?        -------------------------
>> 01/03/2011 14:00:00 EST
>>
>> Any idea why the adding of the interval is converting the result into 
>> EST instead of EDT?
> Because Daylight Saving Time will be over by 1/3/2011?   Does it still 
> happen if you use a
> statically entered time stamp that's during Daylight Saving?
Well now I just feel dumb.  Using the same query, but within daylight 
savings produces the expected result. Thanks for the help.

Mike Ginsburg
Collaborative Fusion, Inc.
mginsburg at collaborativefusion.com