From: Tom Lane <tgl@sss.pgh.pa.us>
To: Francisco Olarte <folarte@peoplecall.com>
cc: dafoer_x@163.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #17366: Error result returned in timestamp2timestamptz,
 expected to be off by one hour
In-reply-to: 
 <CA+bJJbxLHKPOd7RUFckQ+X14+Ob+Swnqonc2m65garJRHsqdEw@mail.gmail.com>
References: <17366-8744a901d10fd9d1@postgresql.org>
 <CA+bJJbxLHKPOd7RUFckQ+X14+Ob+Swnqonc2m65garJRHsqdEw@mail.gmail.com>
Comments: In-reply-to Francisco Olarte <folarte@peoplecall.com>
	message dated "Fri, 14 Jan 2022 12:30:54 +0100"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <3379883.1642173892.1@sss.pgh.pa.us>
Date: Fri, 14 Jan 2022 10:24:52 -0500
Message-ID: <3379884.1642173892@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/3379884.1642173892%40sss.pgh.pa.us>
Precedence: bulk

Francisco Olarte <folarte@peoplecall.com> writes:
> On Fri, 14 Jan 2022 at 11:15, PG Bug reporting form
> <noreply@postgresql.org> wrote:
>> postgres=# set timezone to "PST8PDT";
>> ..
>> postgres=# select (timestamp '2021-03-14 02:00:00')::timestamptz;
>> 2021-03-14 03:00:00-07
>> postgres=# select (timestamp '2021-03-14 03:00:00')::timestamptz;
>> 2021-03-14 03:00:00-07

> You are playing around the DST changes, and timestamp must have unique
> representations, for informal descriptions "time jumps from 2 to 3" is
> fine, when dealing with real data you must decide if it jumps just
> before or just after, it seems your expectations are wrong:

Yeah.  See

https://www.postgresql.org/docs/devel/datetime-invalid-input.html

(I'm pointing you to the devel version of that page because it
contains a correction that hasn't yet propagated into the other
versions)

			regards, tom lane