1 ----- Calendrical issues -----
3 As mentioned in Theory.html, although calendrical issues are out of
4 scope for tzdb, they indicate the sort of problems that we would run
5 into if we extended tzdb further into the past. The following
6 information and sources go beyond Theory.html's brief discussion.
7 They sometimes disagree.
12 Gregorian calendar adopted 1582-12-20.
13 French Revolutionary calendar used 1793-11-24 through 1805-12-31,
14 and (in Paris only) 1871-05-06 through 1871-05-23.
19 From Chris Carrier (1996-12-02):
20 On 1929-10-01 the Soviet Union instituted an "Eternal Calendar"
21 with 30-day months plus 5 holidays, with a 5-day week.
22 On 1931-12-01 it changed to a 6-day week; in 1934 it reverted to the
23 Gregorian calendar while retaining the 6-day week; on 1940-06-27 it
24 reverted to the 7-day week. With the 6-day week the usual days
25 off were the 6th, 12th, 18th, 24th and 30th of the month.
26 (Source: Evitiar Zerubavel, _The Seven Day Circle_)
29 Mark Brader reported a similar story in "The Book of Calendars", edited
30 by Frank Parise (1982, Facts on File, ISBN 0-8719-6467-8), page 377. But:
32 From: Petteri Sulonen (via Usenet)
33 Date: 14 Jan 1999 00:00:00 GMT
36 If your source is correct, how come documents between 1929 and 1940 were
37 still dated using the conventional, Gregorian calendar?
39 I can post a scan of a document dated December 1, 1934, signed by
40 Yenukidze, the secretary, on behalf of Kalinin, the President of the
41 Executive Committee of the Supreme Soviet, if you like.
48 Subject: Re: Gregorian reform - a part of locale?
49 <news:1996Jul6.012937.29190@sq.com>
52 In 1700, Denmark made the transition from Julian to Gregorian. Sweden
53 decided to *start* a transition in 1700 as well, but rather than have one of
54 those unsightly calendar gaps :-), they simply decreed that the next leap
55 year after 1696 would be in 1744 - putting the whole country on a calendar
56 different from both Julian and Gregorian for a period of 40 years.
58 However, in 1704 something went wrong and the plan was not carried through;
59 they did, after all, have a leap year that year. And one in 1708. In 1712
60 they gave it up and went back to Julian, putting 30 days in February that
63 Then in 1753, Sweden made the transition to Gregorian in the usual manner,
64 getting there only 13 years behind the original schedule.
66 (A previous posting of this story was challenged, and Swedish readers
67 produced the following references to support it: "Tideräkning och historia"
68 by Natanael Beckman (1924) and "Tid, en bok om tideräkning och
69 kalenderväsen" by Lars-Olof Lodén (1968).
74 From: "Michael Palmer" [with one obvious typo fixed]
75 Subject: Re: Gregorian Calendar (was Re: Another FHC related question
76 Newsgroups: soc.genealogy.german
77 Date: Tue, 9 Feb 1999 02:32:48 -800
80 The following is a(n incomplete) listing, arranged chronologically, of
81 European states, with the date they converted from the Julian to the
84 04/15 Oct 1582 - Italy (with exceptions), Spain, Portugal, Poland (Roman
85 Catholics and Danzig only)
86 09/20 Dec 1582 - France, Lorraine
89 01 Jan 1583 - Holland, Brabant, Flanders, Hennegau
90 10/21 Feb 1583 - bishopric of Liege (Lüttich)
91 13/24 Feb 1583 - bishopric of Augsburg
92 04/15 Oct 1583 - electorate of Trier
93 05/16 Oct 1583 - Bavaria, bishoprics of Freising, Eichstedt, Regensburg,
95 13/24 Oct 1583 - Austrian Oberelsaß and Breisgau
96 20/31 Oct 1583 - bishopric of Basel
97 02/13 Nov 1583 - duchy of Jülich-Berg
98 02/13 Nov 1583 - electorate and city of Köln
99 04/15 Nov 1583 - bishopric of Würzburg
100 11/22 Nov 1583 - electorate of Mainz
101 16/27 Nov 1583 - bishopric of Strassburg and the margraviate of Baden
102 17/28 Nov 1583 - bishopric of Münster and duchy of Cleve
103 14/25 Dec 1583 - Steiermark
105 06/17 Jan 1584 - Austria and Bohemia
106 11/22 Jan 1584 - Lucerne, Uri, Schwyz, Zug, Freiburg, Solothurn
107 12/23 Jan 1584 - Silesia and the Lausitz
109 02 Feb 1584 - Hungary (legally on 21 Oct 1587)
110 Jun 1584 - Unterwalden
111 01/12 Jul 1584 - duchy of Westfalen
113 16/27 Jun 1585 - bishopric of Paderborn
115 14/25 Dec 1590 - Transylvania
118 02 Sep 1612 - duchy of Prussia
120 13/24 Dec 1614 - Pfalz-Neuburg
122 1617 - duchy of Kurland (reverted to the Julian calendar in
125 1624 - bishopric of Osnabrück
127 1630 - bishopric of Minden
129 15/26 Mar 1631 - bishopric of Hildesheim
133 05/16 Feb 1682 - city of Strassburg
136 01 Mar 1700 - Protestant Germany (including Swedish possessions in
137 Germany), Denmark, Norway
139 12 Jul 1700 - Gelderland, Zutphen
141 12 Dec 1700 - Utrecht, Overijssel
144 12 Jan 1701 - Friesland, Groningen, Zürich, Bern, Basel, Geneva,
145 Turgau, and Schaffhausen
147 1724 - Glarus, Appenzell, and the city of St. Gallen
149 01 Jan 1750 - Pisa and Florence
151 02/14 Sep 1752 - Great Britain
156 1760-1812 - Graubünden
158 The Russian empire (including Finland and the Baltic states) did not
159 convert to the Gregorian calendar until the Soviet revolution of 1917.
161 Source: H. Grotefend, _Taschenbuch der Zeitrechnung des deutschen
162 Mittelalters und der Neuzeit_, herausgegeben von Dr. O. Grotefend
163 (Hannover: Hahnsche Buchhandlung, 1941), pp. 26-28.
167 This file is in the public domain, so clarified as of 2009-05-17 by