From 28f836dacafb3a0e4073bf42a8d2a7529565534b Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Fri, 9 Oct 2026 22:23:34 -0400
Subject: [PATCH] doc:  state PG does not support 8601-optional signed years

Reported-by: Kacper Kuras

Discussion: https://postgr.es/m/178897820483.2258529.4862563749043725162@wrigleys.postgresql.org

Backpatch-through: 19
---
 doc/src/sgml/datatype.sgml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index c71f6362358..6c812c6fa12 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -1879,6 +1879,8 @@ MINUTE TO SECOND
      Date and time input is accepted in almost any reasonable format, including
      ISO 8601, <acronym>SQL</acronym>-compatible,
      traditional <productname>POSTGRES</productname>, and others.
+     (<productname>PostgreSQL</productname> does not support ISO
+     8601-optional signed years.)
      For some formats, ordering of day, month, and year in date input is
      ambiguous and there is support for specifying the expected
      ordering of these fields.  Set the <xref linkend="guc-datestyle"/> parameter