A simpler time zone question
I see that the query "select '2011-11-6 00:59'::timestamptz'" returns a
timestamptz with a time zone of -4, which is correct, since I'm in the
Eastern time zone and the change from EDT to EST will happen at
2011-11-6 02:00. The query "select '2011-11-6 01:01'::timestamptz"
gives me a time zone offset of -5, which tells me that PostgreSQL
assumes that the time change has already happened. Can I count on that
behavior? Will PostgreSQL always assume that an ambiguous time is in
standard instead of daylight time?
Thanks again!
RobR
"Rob Richardson" <Rob.Richardson@rad-con.com> writes:
Will PostgreSQL always assume that an ambiguous time is in
standard instead of daylight time?
Yes, I believe that's even documented somewhere. I think it will also
do that if the time is impossible (eg, 02:30 during a forward DST jump)
regards, tom lane
On 03/28/2011 08:57 AM, Tom Lane wrote:
"Rob Richardson"<Rob.Richardson@rad-con.com> writes:
Will PostgreSQL always assume that an ambiguous time is in
standard instead of daylight time?Yes, I believe that's even documented somewhere. I think it will also
do that if the time is impossible (eg, 02:30 during a forward DST jump)regards, tom lane
I'd love a link to the documentation specifying that behavior. I've
spent a while searching and have thus-far failed to locate it.
If missing, it should be added.
Cheers,
Steve
Steve Crawford <scrawford@pinpointresearch.com> writes:
On 03/28/2011 08:57 AM, Tom Lane wrote:
Yes, I believe that's even documented somewhere. I think it will also
do that if the time is impossible (eg, 02:30 during a forward DST jump)
I'd love a link to the documentation specifying that behavior. I've
spent a while searching and have thus-far failed to locate it.
Hmm. The code is perfectly clear about it, see DetermineTimeZoneOffset:
/*
* It's an invalid or ambiguous time due to timezone transition. Prefer
* the standard-time interpretation.
*/
but right offhand I don't see any mention of ambiguous times in the
likely parts of the documentation.
regards, tom lane