Date: Wed, 10 Jul 2019 14:26:37 -0400
From: Bruce Momjian <bruce@momjian.us>
To: "Jonathan S. Katz" <jkatz@postgresql.org>
Cc: David Harper <adh@sanger.ac.uk>, Tom Lane <tgl@sss.pgh.pa.us>,
	pgsql-docs@lists.postgresql.org
Subject: Re: Ambiguous language in Table 8.13. Special Date/Time Inputs [EXT]
Message-ID: <20190710182637.25x6hxi4o7bht336@momjian.us>
References: <156258047907.1181.11324468080514061996@wrigleys.postgresql.org>
 <20190709033234.ytbltfn25h5wvdbd@momjian.us>
 <8B4735A4-7B46-406A-B4F1-CBFA47D5E1BC@sanger.ac.uk>
 <20190709154825.egarmx2s5jyvft4e@momjian.us>
 <25367.1562687915@sss.pgh.pa.us>
 <1DC28BBD-A4B8-4083-AC83-BD5B012FF3B1@sanger.ac.uk>
 <74c7b4d4-5c0c-29a2-89aa-9395a38e0633@postgresql.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <74c7b4d4-5c0c-29a2-89aa-9395a38e0633@postgresql.org>
User-Agent: NeoMutt/20170113 (1.7.2)
Precedence: bulk

On Wed, Jul 10, 2019 at 01:32:31PM -0400, Jonathan Katz wrote:
> On 7/10/19 6:13 AM, David Harper wrote:
> >> I actually agree with your opinion that "midnight" is fine.
> >> That text has been that way for over fifteen years[1], and
> >> nobody's complained before that it was ambiguous.
> > 
> > Conversely, how many users over the past fifteen years have read that table, and then felt compelled (as I did) to run a query such as
> > 
> >   select 'today'::timestamp,'yesterday'::timestamp,'tomorrow'::timestamp;
> > 
> > on their PostgreSQL cluster to clear the ambiguity for themselves?
> 
> I've heard of one, but only just recently :)
> 
> If we were to s/midnight/00:00:00/ we'd probably want to do it
> everywhere midnight appears. This occurs in a few places in the docs:
> 
> https://www.postgresql.org/docs/current/functions-formatting.html (SSSS)
> https://www.postgresql.org/docs/current/protocol-replication.html
> (XlogData section)
> 
> and there are some various code comments as well.
> 
> Count me as a +0 vote, as I've always interpreted it the way Bruce & Tom
> said upthread, but if we want to change it I can write a patch.

The thing I don't like about 00:00:00 is that it is a lot of information
to say "the start of the day", while I assumed midnight was clear on
that.  If we can find  a way to say "start of the day (midnight)", that
would work.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +