Date: Tue, 2 Dec 2003 14:53:48 +0300
From: "Alexander M. Pravking" <fduch@antar.bryansk.ru>
To: Bob Smith <bsmith@h-e.com>
Cc: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: Problem with intervals
Message-ID: <20031202115348.GK87728@dyatel.antar.bryansk.ru>
References: <AFC6FD04-2485-11D8-A180-0003933DD370@h-e.com>
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On Mon, Dec 01, 2003 at 09:09:20PM -0800, Bob Smith wrote:
> I'm getting an unexpected result using intervals in an expression:
> 
> select ('2003-10-26 0:00:00'::timestamp + '1 day'::interval)::date;
>     date
> ------------
>  2003-10-26
> (1 row)

Try using '2003-10-26 0:00:00'::date + 1;
integers do not lie ;-)


> When I get rid of the date cast it becomes clear what is happening:
> 
> select '2003-10-26 0:00:00'::timestamp + '1 day'::interval;
>         ?column?
> ------------------------
>  2003-10-26 23:00:00-08
> (1 row)
> 
> Is this a Postgres bug, or is this correct SQL behavior?  I'm running 
> Postgres 7.2.2.

It has been discussed several times, Tom Lane offered to add 'day' as
a separate interval unit (like 'second' and 'month' at this moment),
but noone took a shot at it, AFAIK.


Note also, that in 7.3 "timestamp" means "timestamp without time zone",
while in 7.2 it's "timestamp with time zone".


-- 
Fduch M. Pravking