packages/tzdata
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
tzdata/backport-Go-back-to-midnight-transitions-for-France-etc.patch
SuperSix173 f219867b78 sync community patches
2020-10-10 19:03:29 +08:00

185 lines
8.6 KiB
Diff
Raw Blame History

From ccbd7d2eff2449cef48aefcd41dd87034940007b Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 12 Jun 2020 14:35:33 -0700
Subject: [PATCH 13/47] Go back to midnight transitions for France etc.
* NEWS: Simplify.
* africa (Africa/Algiers, Africa/Tunis):
* europe (Europe/Monaco):
Propagate changes from Paris.
* europe (Europe/Paris): Assume 1911 transition was at 00:00.
* theory.html (Accuracy of the tz database): Adjust accordingly.
---
NEWS | 11 ++++-------
africa | 6 +++---
europe | 63 ++++++++++++++++++++++++++++++++++++++++---------------------
theory.html | 9 +++++----
4 files changed, 54 insertions(+), 35 deletions(-)
diff --git a/NEWS b/NEWS
index ec73943..3bcddd0 100644
--- a/NEWS
+++ b/NEWS
@@ -16,13 +16,10 @@ Unreleased, experimental changes
(Thanks to Géza Nyáry.) Also, the 1890 transition to standard
time was on 11-01, not 10-01 (thanks to Michael Deckers).
- The 1911-03-11 French transition from +00:09:21 to +00 is now
- modeled as occurring at 00:09:21, not at 00:01. Clocks reportedly
- stopped at 00:00 for 9 minutes, 21 seconds but this cannot be
- represented in tzdb, so tzdb instead represents the also-common
- practice of keeping an old clock running until the new clock
- started up. Similarly for the 1891-03-16 transition.
- (Thanks to Michael Deckers.)
+ The 1891 French transition was on March 16, not March 15. The
+ 1911-03-11 French transition was at midnight, not a minute later.
+ Monaco's transitions were on 1892-06-01 and 1911-03-29, not
+ 1891-03-15 and 1911-03-11. (Thanks to Michael Deckers.)
Changes to code
diff --git a/africa b/africa
index d5ddbce..567ad90 100644
--- a/africa
+++ b/africa
@@ -89,8 +89,8 @@ Rule Algeria 1980 only - Apr 25 0:00 1:00 S
Rule Algeria 1980 only - Oct 31 2:00 0 -
# See Europe/Paris for PMT-related transitions.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
-Zone Africa/Algiers 0:12:12 - LMT 1891 Mar 16 0:02:51
- 0:09:21 - PMT 1911 Mar 11 0:09:21 # Paris MT
+Zone Africa/Algiers 0:12:12 - LMT 1891 Mar 16
+ 0:09:21 - PMT 1911 Mar 11 # Paris Mean Time
0:00 Algeria WE%sT 1940 Feb 25 2:00
1:00 Algeria CE%sT 1946 Oct 7
0:00 - WET 1956 Jan 29
@@ -1466,7 +1466,7 @@ Rule Tunisia 2006 2008 - Oct lastSun 2:00s 0 -
# See Europe/Paris for PMT-related transitions.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Tunis 0:40:44 - LMT 1881 May 12
- 0:09:21 - PMT 1911 Mar 11 0:09:21 # Paris MT
+ 0:09:21 - PMT 1911 Mar 11 # Paris Mean Time
1:00 Tunisia CE%sT
# Uganda
diff --git a/europe b/europe
index 6e3fe33..e8ec780 100644
--- a/europe
+++ b/europe
@@ -1342,21 +1342,24 @@ Link Europe/Helsinki Europe/Mariehamn
# he announced "Heure nouvelle". See the "Le Petit Journal 1911-03-11".
# https://gallica.bnf.fr/ark:/12148/bpt6k6192911/f1.item.zoom
#
-# From Paul Eggert (2020-06-11):
+# From Michael Deckers (2020-06-12):
+# That "all French clocks stopped" for 00:09:21 is a misreading of French
+# newspapers; this sort of adjustment applies only to certain
+# remote-controlled clocks ("pendules pneumatiques", of which there existed
+# perhaps a dozen in Paris, and which simply could not be set back remotely),
+# but not to all the clocks in all French towns and villages. For instance,
+# the following story in the "Courrier de Saône-et-Loire" 1911-03-11, page 2:
+# only works if legal time was stepped back (was not monotone): ...
+# [One can observe that children who had been born at midnight less 5
+# minutes and who had died at midnight of the old time, would turn out to
+# be dead before being born, time having been set back and having
+# suppressed 9 minutes and 25 seconds of their existence, that is, more
+# than they could spend.]
+#
+# From Paul Eggert (2020-06-12):
# French time in railway stations was legally five minutes behind civil time,
-# which explains why "old time" ran to 00:04:21 instead of to 00:09:21.
-# The Brooklyn Daily Eagle Almanac (1912), page 494, says:
-#
-# ALL CLOCKS STOPPED IN FRANCE.
-# On March 10, 1911, all clocks in the Republic of France were stopped
-# for 9 minutes and 21 seconds. This was in obedience to a measure
-# adopted by the French Senate, which went into effect at midnight....
-# Owing to this change in time a question arose in the French press as
-# to whether or not a child that was born and died within the elapsed
-# time could be said to have legally lived.
-#
-# There are similar stories in the Washington Herald and Washington Times
-# (1911-03-11). The law's text (which Michael Deckers noted is at
+# which explains why railway "old time" ran to 00:04:21 instead of to 00:09:21.
+# The law's text (which Michael Deckers noted is at
# <https://gallica.bnf.fr/ark:/12148/bpt6k2022333z/f2>) says only that
# at 1911-03-11 00:00 legal time was that of Paris mean time delayed by
# nine minutes and twenty-one seconds, and does not say how the
@@ -1364,9 +1367,13 @@ Link Europe/Helsinki Europe/Mariehamn
#
# tzdb has no way to represent stopped clocks. As the railway practice
# was to keep a watch running on "old time" to decide when to restart
-# the other clocks, model this as a transition for "old time" at 00:09:21.
-# Do something similar for the 1891-03-16 transition, which has a similar
-# problem in Algiers and Monaco.
+# the other clocks, this could be modeled as a transition for "old time" at
+# 00:09:21. However, since the law was ambiguous and clocks outside railway
+# stations were probably done haphazardly with the popular impression being
+# that the transition was done at 00:00 "old time", simply leave the time
+# blank; this causes zic to default to 00:00 "old time" which is good enough.
+# Do something similar for the 1891-03-16 transition. There are similar
+# problems in Algiers, Monaco and Tunis.
#
# Shank & Pottenger seem to use '24:00' ambiguously; resolve it with Whitman.
@@ -1434,7 +1441,7 @@ Rule France 1976 only - Sep 26 1:00 0 -
# on PMT-0:09:21 until 1978-08-09, when the time base finally switched to UTC.
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Europe/Paris 0:09:21 - LMT 1891 Mar 16
- 0:09:21 - PMT 1911 Mar 11 0:09:21 # Paris MT
+ 0:09:21 - PMT 1911 Mar 11 # Paris Mean Time
# Shanks & Pottenger give 1940 Jun 14 0:00; go with Excoffier and Le Corre.
0:00 France WE%sT 1940 Jun 14 23:00
# Le Corre says Paris stuck with occupied-France time after the liberation;
@@ -2075,10 +2082,24 @@ Zone Europe/Chisinau 1:55:20 - LMT 1880
2:00 Moldova EE%sT
# Monaco
-# See Europe/Paris for PMT-related transitions.
+#
+# From Michael Deckers (2020-06-12):
+# In the "Journal de Monaco" of 1892-05-24, online at
+# https://journaldemonaco.gouv.mc/var/jdm/storage/original/application/b1c67c12c5af11b41ea888fb048e4fe8.pdf
+# we read: ...
+# [In virtue of a Sovereign Ordinance of the May 13 of the current [year],
+# legal time in the Principality will be set to, from the date of June 1,
+# 1892 onwards, to the meridian of Paris, as in France.]
+# In the "Journal de Monaco" of 1911-03-28, online at
+# https://journaldemonaco.gouv.mc/var/jdm/storage/original/application/de74ffb7db53d4f599059fe8f0ed482a.pdf
+# we read an ordinance of 1911-03-16: ...
+# [Legal time in the Pricipality will be set, from the date of promulgation
+# of the present ordinance, to legal time in France. Consequently, legal
+# time will be retarded by 9 minutes and 21 seconds.]
+#
# Zone NAME STDOFF RULES FORMAT [UNTIL]
-Zone Europe/Monaco 0:29:32 - LMT 1891 Mar 16 0:20:11
- 0:09:21 - PMT 1911 Mar 11 0:09:21 # Paris MT
+Zone Europe/Monaco 0:29:32 - LMT 1892 Jun 1
+ 0:09:21 - PMT 1911 Mar 29 # Paris Mean Time
0:00 France WE%sT 1945 Sep 16 3:00
1:00 France CE%sT 1977
1:00 EU CE%sT
diff --git a/theory.html b/theory.html
index de105f2..1a5b568 100644
--- a/theory.html
+++ b/theory.html
@@ -692,10 +692,11 @@ href="https://www.dissentmagazine.org/blog/booked-a-global-history-of-time-vanes
</li>
<li>
The <code><abbr>tz</abbr></code> database cannot represent stopped clocks.
- However, on 1911-03-11 at 00:00, French clocks were changed by
- stopping them for 9 minutes, 21 seconds. This is approximated
- in <code><abbr>tz</abbr></code> as a transition from 00:09:21 back
- to 00:00:00 that day.
+ However, on 1911-03-11 at 00:00, some public-facing French clocks
+ were changed by stopping them for a few minutes to effect a transition.
+ The <code><abbr>tz</abbr></code> database models this via a
+ backward transition; the relevant French legislation does not
+ specify exactly how the transition was to occur.
</li>
<li>
Sometimes historical timekeeping was specified more precisely
--
1.8.3.1
Reference in New Issue View Git Blame Copy Permalink