Date: Thu, 14 May 2026 08:05:23 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Robert Treat <rob@xzilla.net>
Cc: Kirk Parker <khp@equatoria.us>, Richard Neill <rjn@richardneill.org>,
	github@richardneill.org, pgsql-docs@lists.postgresql.org
Subject: Re: Please clarify that Timestamp with Timezone doesn't preserve the
 timezone.
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On Thu, May 14, 2026 at 07:57:21AM -0400, Robert Treat wrote:
> > I see your point.  I went with adding the wording "no time zone
> > adjustment" and "with time zone adjustment" in the table.  Patch
> > attached.  You can see the output at:
> 
> The quibble I have with the term "time zone adjustment" is that it
> implies there will be some adjustment, but while you can change your
> timezone preferences to display a timestamptz value in whatever time
> zone you want, the value itself is never adjusted; it is stored as a
> universal moment in time that doesn't change, regardless of the window
> dressing around it. For this reason I have taken to describing that
> difference between the two as that timestamptz stores the date and
> time with timezone awareness, and timestamp is date and time with no
> timezone awareness. Perhaps that might work better here as well?

I used "adjustment" because the value is adjusted on input, and adjusted
on output.  I would say the value is not "aware" of the time zone
because once it is internally stored as UTC it is no longer aware of the
original time zone.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Do not let urgent matters crowd out time for investment in the future.