Thanks, I installed the attached proposed further commentary patch.
From e03298240e13d30787e671dffd9148e52e9afffd Mon Sep 17 00:00:00 2001
From: Paul Eggert <[email protected]>
Date: Tue, 22 Jul 2025 16:41:37 -0700
Subject: [PROPOSED] More commentary about 1923 Paris
* europe: Add another comment (thanks to Robert H. van Gent).
---
europe | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/europe b/europe
index 69beb397..24ab6b59 100644
--- a/europe
+++ b/europe
@@ -1389,6 +1389,12 @@ Rule France 1920 only - Oct 23 23:00s 0 -
Rule France 1921 only - Mar 14 23:00s 1:00 S
Rule France 1921 only - Oct 25 23:00s 0 -
Rule France 1922 only - Mar 25 23:00s 1:00 S
+# From Robert H. van Gent (2025-07-22):
+# There is a curious history behind the erroneous date for the start of
+# daylight saving in France in 1923 as listed in the current issues of
+# the Annuaire du Bureau des Longitudes. [See:]
+# https://lists.iana.org/hyperkitty/list/[email protected]/message/MYQEJMSXO2AIEZ3UIXZKMTTAIPY7KNT2/
+# From Paul Eggert (2025-07-22):
# DISHO writes that a law of 1923-05-24 specified 3rd Sat in Apr at 23:00 to 1st
# Sat in Oct at 24:00; and that in 1930, because of Easter, the transitions
# were Apr 12 and Oct 5. Apparently spring 1923 was tricky: the New York
@@ -1397,7 +1403,8 @@ Rule France 1922 only - Mar 25 23:00s 1:00 S
# pass the bill authorizing daylight saving time for this year in
# France.... The bill must now go before the Senate ...".
# Use the 2020 Annuaire dates, except for spring 1923 where
-# Shanks & Pottenger's May 26 seems more plausible.
+# Shanks & Pottenger's May 26 matches the dates given in the 1924 and
+# 1961-2001 issues of the Annuaire.
Rule France 1922 1938 - Oct Sat>=1 23:00s 0 -
Rule France 1923 only - May 26 23:00s 1:00 S
Rule France 1924 only - Mar 29 23:00s 1:00 S
--
2.48.1
