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From: Michael Glaesemann <grzm@seespotcode.net>
Subject: Re: subtract a day from the NOW function
Date: Thu, 7 Jun 2007 12:27:03 -0500
To: "Campbell, Lance" <lance@uiuc.edu>

> From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-=20
> owner@postgresql.org] On Behalf Of Campbell, Lance
> Sent: Thursday, June 07, 2007 11:09 AM
> To: pgsql-sql@postgresql.org
> Subject: [SQL] subtract a day from the NOW function
>  SELECT some_timestamp WHERE to_char(some_timestamp, =91YYYYMMDD=92) > =
=20
> (to_char(now(), =91YYYYMMDD=92) =96 1 day);

On Jun 7, 2007, at 11:36 , Campbell, Lance wrote:
> select to_char((now() - interval '1 day'), 'YYYYMMDD');

Why are you using to_char? Timestamps and dates support comparisons =20
just fine.

SELECT CURRENT_TIMESTAMP > (CURRENT_TIMESTAMP - INTERVAL '1 day');
?column?
----------
t
(1 row)

CURRENT_TIMESTAMP is SQL-spec for now().

If you're specifically looking to compare dates rather than =20
timestamps, you can cast timestamp to date:

SELECT CURRENT_DATE > (CURRENT_DATE - INTERVAL '1 day')::date;
?column?
----------
t
(1 row)

You could also use the age function:

SELECT age(CURRENT_TIMESTAMP) <  INTERVAL '1 day';

SELECT age(CURRENT_TIMESTAMP) <  INTERVAL '1 day';
?column?
----------
t
(1 row)

Hope that helps.

Michael Glaesemann
grzm seespotcode net