-# @(#)europe 8.18
# <pre>
+# @(#)europe 8.21
+# This file is in the public domain, so clarified as of
+# 2009-05-17 by Arthur David Olson.
# This data is by no means authoritative; if you think you know better,
# go ahead and edit the file (and please send any changes to
# mean time in preference to apparent time -- Geneva from 1780 ....
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
# From Whitman (who writes ``Midnight?''):
-Rule Swiss 1940 only - Nov 2 0:00 1:00 S
-Rule Swiss 1940 only - Dec 31 0:00 0 -
+# Rule Swiss 1940 only - Nov 2 0:00 1:00 S
+# Rule Swiss 1940 only - Dec 31 0:00 0 -
# From Shanks & Pottenger:
-Rule Swiss 1941 1942 - May Sun>=1 2:00 1:00 S
-Rule Swiss 1941 1942 - Oct Sun>=1 0:00 0 -
+# Rule Swiss 1941 1942 - May Sun>=1 2:00 1:00 S
+# Rule Swiss 1941 1942 - Oct Sun>=1 0:00 0 -
+
+# From Alois Treindl (2008-12-17):
+# I have researched the DST usage in Switzerland during the 1940ies.
+#
+# As I wrote in an earlier message, I suspected the current tzdata values
+# to be wrong. This is now verified.
+#
+# I have found copies of the original ruling by the Swiss Federal
+# government, in 'Eidgen[o]ssische Gesetzessammlung 1941 and 1942' (Swiss
+# federal law collection)...
+#
+# DST began on Monday 5 May 1941, 1:00 am by shifting the clocks to 2:00 am
+# DST ended on Monday 6 Oct 1941, 2:00 am by shifting the clocks to 1:00 am.
+#
+# DST began on Monday, 4 May 1942 at 01:00 am
+# DST ended on Monday, 5 Oct 1942 at 02:00 am
+#
+# There was no DST in 1940, I have checked the law collection carefully.
+# It is also indicated by the fact that the 1942 entry in the law
+# collection points back to 1941 as a reference, but no reference to any
+# other years are made.
+#
+# Newspaper articles I have read in the archives on 6 May 1941 reported
+# about the introduction of DST (Sommerzeit in German) during the previous
+# night as an absolute novelty, because this was the first time that such
+# a thing had happened in Switzerland.
+#
+# I have also checked 1916, because one book source (Gabriel, Traite de
+# l'heure dans le monde) claims that Switzerland had DST in 1916. This is
+# false, no official document could be found. Probably Gabriel got misled
+# by references to Germany, which introduced DST in 1916 for the first time.
+#
+# The tzdata rules for Switzerland must be changed to:
+# Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S
+# Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 -
+#
+# The 1940 rules must be deleted.
+#
+# One further detail for Switzerland, which is probably out of scope for
+# most users of tzdata:
+# The zone file
+# Zone Europe/Zurich 0:34:08 - LMT 1848 Sep 12
+# 0:29:44 - BMT 1894 Jun #Bern Mean Time
+# 1:00 Swiss CE%sT 1981
+# 1:00 EU CE%sT
+# describes all of Switzerland correctly, with the exception of
+# the Cantone Geneve (Geneva, Genf). Between 1848 and 1894 Geneve did not
+# follow Bern Mean Time but kept its own local mean time.
+# To represent this, an extra zone would be needed.
+
+# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
+Rule Swiss 1941 1942 - May Mon>=1 1:00 1:00 S
+Rule Swiss 1941 1942 - Oct Mon>=1 2:00 0 -
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Europe/Zurich 0:34:08 - LMT 1848 Sep 12
0:29:44 - BMT 1894 Jun # Bern Mean Time
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