In most societies a calendar reform is an extraordinary event. Adoption of a calendar depends on the forcefulness with which it is introduced and on the willingness of society to accept it. For example, the acceptance of the Gregorian calendar as a worldwide standard spanned more than three centuries.
The legal code of the United States does not specify an official national calendar. Use of the Gregorian calendar in the United States stems from an Act of Parliament of the United Kingdom in 1751, which specified use of the Gregorian calendar in England and its colonies. However, its adoption in the United Kingdom and other countries was fraught with confusion, controversy, and even violence (Bates, 1952; Gingerich, 1983; Hoskin, 1983). It also had a deeper cultural impact through the disruption of traditional festivals and calendrical practices (MacNeill, 1982).
When did countries change from Julian to Gregorian calendars?
The papal bull of February 1582 decreed that 10 days should be dropped from October 1582 so that 15 October should follow immediately after 4 October, and from then on the reformed calendar should be used.
This was observed in Italy, Poland, Portugal, and Spain. Other Catholic countries followed shortly after, but Protestant countries were reluctant to change, and the Greek orthodox countries didn’t change until the start of the 1900s.
Changes in the 1500s required 10 days to be dropped. Changes in the 1600s required 10 days to be dropped. Changes in the 1700s required 11 days to be dropped. Changes in the 1800s required 12 days to be dropped. Changes in the 1900s required 13 days to be dropped. For example, when Soviet Russia undertook its calendar reform in February 1918, they moved from the Julian calendar to the Gregorian. This move resulted in a loss of 13 days, so that February 1, 1918, became February 14.
The following list contains the dates for changes in a number of countries. It is very strange that in many cases there seems to be some doubt among authorities about what the correct days are. Different sources give very different dates in some cases. The list below does not include all the different opinions about when the change took place.
→ See the British Calendar Act of 1751.
Albania: | December 1912 |
Austria: | Different regions on different dates Brixen, Salzburg and Tyrol: 5 Oct 1583 was followed by 16 Oct 1583 Carinthia and Styria: 14 Dec 1583 was followed by 25 Dec 1583 See also Czechoslovakia and Hungary |
Belgium: | Then part of the Netherlands |
Bulgaria: | 31 Mar 1916 was followed by 14 Apr 1916 |
Canada: | Different areas changed at different times. Newfoundland and Hudson Bay coast: 2 Sep 1752 was followed by 14 Sep 1752 Mainland Nova Scotia: Gregorian 1605 - 13 Oct 1710 Julian 2 Oct 1710 - 2 Sep 1752 Gregorian since 14 Sep 1752 Rest of Canada: Gregorian from first European settlement |
China: | The Gregorian calendar replaced the Chinese calendar in either 1912 or 1929 (depending on which authorities you believe). |
Czechoslovakia (i.e. Bohemia and Moravia): | 6 Jan 1584 was followed by 17 Jan 1584 |
Denmark (including Norway): | 18 Feb 1700 was followed by 1 Mar 1700 |
Egypt: | 1875 |
Estonia: | 31 Jan 1918 was followed by 14 Feb 1918 |
Finland: | Then part of Sweden. (Note, however, that Finland later became part of Russia, which then still used the Julian calendar. The Gregorian calendar remained official in Finland, but some use of the Julian calendar was made.) |
France: | 9 Dec 1582 was followed by 20 Dec 1582 Alsace: 5 Feb 1682 was followed by 16 Feb 1682 Lorraine: 16 Feb 1760 was followed by 28 Feb 1760 Strasbourg: February 1682 |
Germany: | Different states on different dates: Catholic states on various dates in 1583-1585 Prussia: 22 Aug 1610 was followed by 2 Sep 1610 Protestant states: 18 Feb 1700 was followed by 1 Mar 1700 (Many local variations) |
Great Britain and Dominions: | 2 Sep 1752 was followed by 14 Sep 1752 |
Greece: | 9 Mar 1924 was followed by 23 Mar 1924 (Some sources say 1916 and 1920) |
Hungary: | 21 Oct 1587 was followed by 1 Nov 1587 |
Ireland: | See Great Britain |
Italy: | 4 Oct 1582 was followed by 15 Oct 1582 |
Japan: | The Gregorian calendar was introduced to supplement the traditional Japanese calendar on 1 Jan 1873. |
Latvia: | During German occupation 1915 to 1918 |
Lithuania: | 1915 |
Luxemburg: | 14 Dec 1582 was followed by 25 Dec 1582 |
Netherlands (including Belgium): | Zeeland, Brabrant, and the "Staten Generaal": 14 Dec 1582 was followed by 25 Dec 1582 Holland: 1 Jan 1583 was followed by 12 Jan 1583 Limburg and the southern provinces (currently Belgium): 20 Dec 1582 was followed by 31 Dec 1582 or 21 Dec 1582 was followed by 1 Jan 1583 Groningen: 10 Feb 1583 was followed by 21 Feb 1583 Went back to Julian in the summer of 1594 31 Dec 1700 was followed by 12 Jan 1701 Gelderland: 30 Jun 1700 was followed by 12 Jul 1700 Utrecht and Overijssel: 30 Nov 1700 was followed by 12 Dec 1700 Friesland: 31 Dec 1700 was followed by 12 Jan 1701 Drenthe: 30 Apr 1701 was followed by 12 May 1701 |
Norway: | Then part of Denmark. |
Poland: | 4 Oct 1582 was followed by 15 Oct 1582 |
Portugal: | 4 Oct 1582 was followed by 15 Oct 1582 |
Romania: | 31 Mar 1919 was followed by 14 Apr 1919 (The Greek Orthodox parts of the country may have changed later) |
Russia: | 31 Jan 1918 was followed by 14 Feb 1918 (In the eastern parts of the country the change may not have occured until 1920) |
Scotland: | See Great Britain. |
Spain: | 4 Oct 1582 was followed by 15 Oct 1582 |
Sweden (including Finland): | 17 Feb 1753 was followed by 1 Mar 1753 (see note below) |
Switzerland: | Catholic cantons: 1583, 1584 or 1597 Protestant cantons: 31 Dec 1700 was followed by 12 Jan 1701 (Many local variations) |
Turkey: | Gregorian calendar introduced 1 Jan 1927 |
USA: | Different areas changed at different times. Along the Eastern seaboard: With Great Britain in 1752. Mississippi valley: With France in 1582. Texas, Florida, California, Nevada, Arizona, New Mexico: With Spain in 1582 Washington, Oregon: With Britain in 1752. Alaska: October 1867 when Alaska became part of the USA. |
Wales: | See Great Britain |
Yugoslavia: | 1919 |
Sweden has a curious history. Sweden decided to make a gradual change from the Julian to the Gregorian calendar. By dropping every leap year from 1700 through 1740 the eleven superfluous days would be omitted and from 1 Mar 1740 they would be in sync with the Gregorian calendar. (But in the meantime they would be in sync with nobody!)
So 1700 (which should have been a leap year in the Julian calendar) was not a leap year in Sweden. However, by mistake 1704 and 1708 became leap years. This left Sweden out of synchronisation with both the Julian and the Gregorian world, so they decided to go back to the Julian calendar. In order to do this, they inserted an extra day in 1712, making that year a double leap year! So in 1712, February had 30 days in Sweden.
Later, in 1753, Sweden changed to the Gregorian calendar by dropping 11 days like everyone else.