A kind person on the pgsql-general list told me.
"This appears to be a simple typo in the pg_proc entry for the function.
The underlying C code thinks it is returning a timestamp without time
zone, but that's not what the pg_proc entry has.
You can fix this in an existing database by doing
UPDATE pg_proc SET prorettype = 1114 WHERE prosrc = 'timestamptz_izone';"
This fixed the problem for me.
Josh.
On March 13, 2003 10:12 pm, Joshua Moore-Oliva wrote:
> When selecting with the AT TIME ZONE or timezone function, the returned
> value is not always a timestamp. This is inconsistent with the
> documentation.
>
> To reproduce this problem, run these two queries.
>
> SELECT now() AT TIME ZONE 'EST'
>
> returns 2003-03-13 21:27:14.63401-05
>
> SELECT now() AT TIME ZONE INTERVAL '-05:00'
>
> returns 1167 days 21:54:30.952135995
>
> (Queries were run at different time, the problem is that it is returning an
> interval instead of a timestamp).
>
> When I attempt to cast the interval as a timestamp it gives me an error
> saying that it's not possible.
>
> I am pretty sure this is a bug. Following is supoprting dpcumentation from
> the manual.
>
> From the documentation
>
> In these expressions, the desired time zone can be specified either as a
> text string (e.g., 'PST') or as an interval (e.g., INTERVAL '-08:00').
>
>
> Examples (supposing that TimeZone is PST8PDT):
>
> SELECT TIMESTAMP '2001-02-16 20:38:40' AT TIME ZONE 'MST';
> Result: 2001-02-16 19:38:40-08
>
> SELECT TIMESTAMP WITH TIME ZONE '2001-02-16 20:38:40-05' AT TIME ZONE
> 'MST'; Result: 2001-02-16 18:38:40
>
> The first example takes a zone-less timestamp and interprets it as MST
> time (GMT-7) to produce a UTC timestamp, which is then rotated to PST
> (GMT-8) for display. The second example takes a timestamp specified in EST
> (GMT-5) and converts it to local time in MST (GMT-7).
>
>
> The function timezone(zone, timestamp) is equivalent to the SQL-compliant
> construct timestamp AT TIME ZONE zone.
>
> Josh.
>
>
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