On Fri, Feb 15, 2013 at 09:27:40PM +0000, nick.baxter@gmail.com wrote:
> The following bug has been logged on the website:
>
> Bug reference: 7886
> Logged by: Nick Baxter
> Email address: nick.baxter@gmail.com
> PostgreSQL version: 9.0.3
> Operating system: Linux 2.6.18
> Description:
>
> 9.9.2. indicates that date_trunc can be called with a date value (which will
> be cast to a timestamp). And regardless of the input, that the result will
> be of type timestamp. When I call it with a date, I get a timestamp with
> time zone instead, as indicated by the psql output.
>
> # select date_trunc('month',date '2013-2-15');
> date_trunc
> ------------------------
> 2013-02-01 00:00:00-06
> (1 row)
That documentation often uses timestamp when it means timestamp with
time zone. Not sure why that is.
\df shows the supported functions:
test=> \df date_trunc
List of functions
Schema | Name | Result data type | Argument data types | Type
------------+------------+-----------------------------+-----------------------------------+--------
pg_catalog | date_trunc | interval | text, interval | normal
pg_catalog | date_trunc | timestamp without time zone | text, timestamp without time zone | normal
pg_catalog | date_trunc | timestamp with time zone | text, timestamp with time zone | normal
This returns a timestamp without time zone:
test=> select date_trunc('month',timestamp '2013-2-15');
date_trunc
---------------------
2013-02-01 00:00:00
(1 row)
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ It's impossible for everything to be true. +
