Re: Re: Time AT TIME ZONE: false result using offset instead of time zone name

On 02/12/2014 12:24 AM, rawi wrote:
> Adrian Klaver-3 wrote
>>> On 02/10/2014 11:54 PM, rawi wrote:
>>> [...]
>>> SELECT CURRENT_TIMESTAMP AT TIME ZONE 'UTC+01';
>>>
>>> timezone
>>> timestamp without time zone
>>> ---------------------------
>>> 2014-02-11 06:23:07.043479
>>>
>>> !!! Two hours earlyer, one hour to the east (Azores), not to the west of
>>> Greenwich.
>>> To get my time one hour west from Greenwich I have to ask:
>>>
>>> SELECT CURRENT_TIMESTAMP AT TIME ZONE 'UTC-01';
>>>
>>> Is this inverse calculation intently?
>>
>> Yes.
>>
>> http://www.postgresql.org/docs/9.3/interactive/datatype-datetime.html#DATATYPE-TIMEZONES
>>
>> 8.5.3. Time Zones
>>
>> .. Another issue to keep in mind is that in POSIX time zone names,
>> positive offsets are used for locations west of Greenwich. Everywhere
>> else, PostgreSQL follows the ISO-8601 convention that positive timezone
>> offsets are east of Greenwich
>
> Oh... oh... Disconcerting... I've just learned, that even javascript is
> returning negative offsets for western situated browsers...

Welcome to the wacky world of time, it is all relative:) The choices are
handle everything as UTC until you present to the end user or use actual
timezones, for example, America/Los_Angeles. To illustrate, in your
original post you said:

"But it would be easier to ask a specific time offset (got from a client
around the world), so for me +01 hour"

Do you know if that offset supplied by the client was POSIX or ISO in
its sign?

>
> Thank you!
> Regards, Rawi
>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com