On Thu, May 14, 2026 at 08:17:36AM -0400, Dave Cramer wrote:
>
>
> On Thu, 14 May 2026 at 08:05, Bruce Momjian <[email protected]> wrote:
>
> 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.
>
>
> Adjusted seems like the wrong word. I think the correct word is converted.
Okay, here is the patch with "conversion".
--
Bruce Momjian <[email protected]> https://momjian.us
EDB https://enterprisedb.com
Do not let urgent matters crowd out time for investment in the future.
diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index d8d91678e86..9a3b8cfbc1d 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -252,25 +252,25 @@
<row>
<entry><type>time [ (<replaceable>p</replaceable>) ] [ without time zone ]</type></entry>
<entry></entry>
- <entry>time of day (no time zone)</entry>
+ <entry>time of day (no time zone conversion)</entry>
</row>
<row>
<entry><type>time [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
<entry><type>timetz</type></entry>
- <entry>time of day, including time zone</entry>
+ <entry>time of day, including time zone conversion</entry>
</row>
<row>
<entry><type>timestamp [ (<replaceable>p</replaceable>) ] [ without time zone ]</type></entry>
<entry></entry>
- <entry>date and time (no time zone)</entry>
+ <entry>date and time (no time zone conversion)</entry>
</row>
<row>
<entry><type>timestamp [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
<entry><type>timestamptz</type></entry>
- <entry>date and time, including time zone</entry>
+ <entry>date and time, including time zone conversion</entry>
</row>
<row>
@@ -1768,7 +1768,7 @@ SELECT 'abc \153\154\155 \052\251\124'::bytea;
<row>
<entry><type>timestamp [ (<replaceable>p</replaceable>) ] [ without time zone ]</type></entry>
<entry>8 bytes</entry>
- <entry>both date and time (no time zone)</entry>
+ <entry>both date and time (no time zone conversion)</entry>
<entry>4713 BC</entry>
<entry>294276 AD</entry>
<entry>1 microsecond</entry>
@@ -1776,7 +1776,7 @@ SELECT 'abc \153\154\155 \052\251\124'::bytea;
<row>
<entry><type>timestamp [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
<entry>8 bytes</entry>
- <entry>both date and time, with time zone</entry>
+ <entry>both date and time, with time zone conversion</entry>
<entry>4713 BC</entry>
<entry>294276 AD</entry>
<entry>1 microsecond</entry>
@@ -1800,7 +1800,7 @@ SELECT 'abc \153\154\155 \052\251\124'::bytea;
<row>
<entry><type>time [ (<replaceable>p</replaceable>) ] with time zone</type></entry>
<entry>12 bytes</entry>
- <entry>time of day (no date), with time zone</entry>
+ <entry>time of day (no date), with time zone conversion</entry>
<!-- see MAX_TZDISP_HOUR in datatype/timestamp.h -->
<entry>00:00:00+1559</entry>
<entry>24:00:00-1559</entry>
@@ -2263,8 +2263,9 @@ TIMESTAMP WITH TIME ZONE '2004-10-19 10:23:54+02'
then it is assumed to be in the time zone indicated by the system's
<xref linkend="guc-timezone"/> parameter, and is converted to UTC using the
offset for the <varname>timezone</varname> zone.
- In either case, the value is stored internally as UTC, and the
- originally stated or assumed time zone is not retained.
+ In either case, the value is stored internally as UTC. The
+ originally stated or assumed time zone is not retained and
+ <emphasis>cannot</emphasis> be retrieved later.
</para>
<para>
