Article: 26640 of sci.math

This is an excerpt from a post which was made to comp.lang.c some time
ago by one Bob Douglas:
 
| By and large, Catholic countries adopted the Gregorian calendar at or
| about the time Gregory's edict stated. Protestant countries didn't;
| but sooner or later they had to conform as their calendars were getting
| more and more out of step with the seasons as the centuries passed.
| 
| Below are (sometimes approximate) dates of calendar conversion for
| many countries. Surprisingly, there seems to be considerable doubt
| over when some areas changed. Information below is taken from
| 
|       Explanatory Supplement to the Astronomical Ephemeris
|       and the American Ephemeris and Nautical Almanac
| 
|       Her Majesty's Stationary Office, London, 1961
| 
| This gives several other references, mainly obscure German works.
| 
| Where it is known exactly, the changeover is given in the form
| 
|       last Julian date - first Gregorian date
| 
| otherwise approximate dates (usually just years) are given.
| 
| Remember that many European countries had very different borders at the
| time of the changeover to those they have now (e.g. Poland, Hungary).
| There have been changes in political authority too. The German states
| particularly formed just a linguistic area comprising (roughly) modern
| Austria, Germany, Czechoslovakia and Switzerland; and different political
| entities (and sometimes even the ecclesiastical and civil authorities in
| one area) adopted the Gregorian calendar at different dates. See the
| above reference for more details.
| 
| ==========================================================================
| 
| Alaska                             Gregorian calendar adopted when the USA
|                                    bought Alaska from Russia (18 October 1867)
| 
| Albania                            December 1912
| 
| American Colonies                  See Great Britain
| 
| Austria                            Different regions on different dates
|                                         6 Oct 1583 - 16 Oct 1583
|                                        15 Dec 1583 - 25 Dec 1583
| 
| Belgium                            Different authorities say
|                                        15 Dec 1582 - 25 Dec 1582
|                                        22 Dec 1582 -  1 Jan 1583
| 
| Bulgaria                           Different authorities say
|                                        Sometime in 1912
|                                        19 Mar 1916 -  1 Apr 1916
| 
| China                              Different authorities say
|                                        19 Dec 1911 -  1 Jan 1912
|                                        19 Dec 1928 -  1 Jan 1929
| 
| Czechoslovakia (i.e. Bohemia and Moravia)
| 				    7 Jan 1584 - 17 Jan 1584
| 
| Denmark (including Norway)         19 Feb 1700 - 1 Mar 1700
| 
| Egypt                              1875
| 
| Estonia                            January 1918
| 
| Finland                            Then part of Sweden (q.v.)
| 
| France                             10 Dec 1582 - 20 Dec 1582
| 
| German States                      Different states on different dates:
|                                        14 Feb 1583 - 24 Feb 1583
|                                         5 Oct 1583 - 15 Oct 1583
|                                         6 Oct 1583 - 16 Oct 1583
|                                         3 Nov 1583 - 13 Nov 1583
|                                         4 Nov 1583 - 14 Nov 1583
|                                         5 Nov 1583 - 15 Nov 1583
|                                        12 Nov 1583 - 22 Nov 1583
|                                        17 Nov 1583 - 27 Nov 1583
|                                         7 Jan 1584 - 17 Jan 1584
|                                        13 Jan 1584 - 23 Jan 1584
|                                         2 Jul 1584 - 12 Jul 1584
|                                        17 Jun 1585 - 27 Jun 1585
|                                        23 Aug 1610 -  2 Sep 1610   (a)
|                                        14 Dec 1615 - 24 Dec 1615
|                                        16 Mar 1631 - 26 Mar 1631
|                                        19 Feb 1700 -  1 Mar 1700   (b)
|                                    Note:
|                                    (a) Prussia
|                                    (b) Protestant Germany
| 
| Great Britain and Dominions         3 Sep 1752 - 14 Sep 1752
| 
| Greece                             10 Mar 1924 - 23 Mar 1924
| 
| Hungary                            22 Oct 1587 -  1 Nov 1587
| 
| Italy                               5 Oct 1582 - 15 Oct 1582
| 
| Japan                              19 Dec 1918 -  1 Jan 1919
| 
| Latvia                             During German occupation 1915 to 1918
| 
| Lithuania                          1915
| 
| Luxemburg                          15 Dec 1582 - 25 Dec 1582
| 
| Netherlands                        Catholic:    various 1582 or 1583
|                                    Protestant:  various 1700 or 1701
| 
| Norway                             Then under Danish rule. See Denmark
| 
| Poland                              5 Oct 1582 - 15 Oct 1582
| 
| Portugal                            5 Oct 1582 - 15 Oct 1582
| 
| Romania                             1 Apr 1919 - 14 Apr 1919
| 
| Spain                               5 Oct 1582 - 15 Oct 1882
| 
| Sweden (including Finland)         18 Feb 1753 - 1 Mar 1753
| 
| Switzerland                        Varied with the Cantons. Generally one of
|                                        12 Jan 1584 - 22 Jan 1584
|                                         1 Jan 1701 - 12 Jan 1701
| 
| Turkey                             19 Dec 1926 -  1 Jan 1927
| 
| Yugoslavia (as it then was)        1919
| 
| UK                                 See Great Britain
| 
| USA (then American colonies)       See Great Britain
| 
| USSR (as it then was)               1 Feb 1918 - 14 Feb 1918
| -- 
| Bob Douglas              Computing Services, University of Oxford

==============================================================================

               Dennis Paul Himes    <>    dennis@cadkey.com
 
Disclaimer: "True, I talk of dreams; which are the children of an idle
brain, begot of nothing but vain fantasy; which is as thin of substance as
the air."                      - Romeo & Juliet, Act I Scene iv Verse 96-99