Dates of the Gregorian Reform
The table below lists official adoption dates, with as much precision as I've been able to discover. Simply because the government told people to convert, however, does not mean they did so. Because of religiously inspired opposition to the conversion, both calendars were often in use in regions where there was a religiously mixed population.
The political map has changed enormously since the 16th century. Areas are listed more or less under their current affiliations, but some regions, e.g. Silesia, have been divided up since the conversion, and in these instances I've been arbitrary (Silesia is listed under Poland). This table lists only dates for those countries already using the Julian calendar before adopting the Gregorian one. Countries like Japan and China are therefore not shown. I have also not given separate entries for all the countries that formed out of the Spanish colonial empire. See under Spain for them.
| Country/Region | Last Julian | First Gregorian |
|---|---|---|
| Albania | 1912.12 | 1912.12 |
| Austria | ||
| Tyrol | 1583.10.5 | 1583.10.16 |
| Carynthia, Styria | 1583.12.14 | 1583.12.25 |
| Belgium | ||
| Spanish Provinces | 1582.12.21 | 1583.1.1 |
| Liège (diocese) | 1583.2.10 | 1583.2.21 |
| Bulgaria | 1915.11.1 | 1915.11.14 |
| Czech Republic (Bohemia, Moravia) | 1584.1.6 | 1584.1.17 |
| Denmark | 1700.2.18 | 1700.3.1 |
| Færø Islands | 1700.11.16 | 1700.11.28 |
| Estonia | 1918.2.1 | 1918.2.15 |
| Finland (see note on Sweden) | 1753.2.17 | 1753.3.1 |
| France | 1582.12.9 | 1582.12.20 |
| Alsace | 1648 | 1648 |
| Strasbourg | 1682.2.5 | 1682.2.16 |
| Germany, Catholic Regions | ||
| Augsburg | 1583.2.13 | 1583.2.24 |
| Baden (margravate) | 1583.11.16 | 1583.11.27 |
| Bavaria (diocese) | 1583.10.5 | 1583.10.16 |
| Cologne (archdiocese, incl. Aachen) | 1583.11.3 | 1583.11.14 |
| Jülich | 1583.11.2 | 1583.11.13 |
| Mainz | 1583.11.11 | 1583.11.22 |
| Münster (city and archdiocese) | 1583.11.16 | 1583.11.27 |
| Strasbourg (diocese only) | 1583.11.16 | 1583.11.27 |
| Trier | 1583.10.4 | 1583.10.15 |
| Würzburg (diocese) | 1583.11.4 | 1583.11.15 |
| Germany, Protestant Regions | ||
| Hildesheim (diocese) | 1631.3.15 | 1631.3.26 |
| Kurland | 1617 | 1617 |
| Minden | 1668.2.1 | 1668.2.12 |
| Neuburg (palatinate) | 1615.12.13 | 1615.12.24 |
| Osnabrück (diocese) | 1624 | 1624 |
| Paderborn (diocese) | 1585.6.16 | 1585.6.27 |
| Prussia | 1610.8.22 | 1610.9.2 |
| Westphalia | 1584.7.1 | 1584.7.12 |
| All Others | 1700.2.18 | 1700.3.1 |
| Great Britain | 1752.9.2 | 1752.9.14 |
| Greece | 1916.7.14 | 1916.7.28 |
| Holy Roman Empire, Imperial Court (see also Germany, Austria, Hungary, Czech Republic) |
1584.1.6 | 1584.1.17 |
| Hungary | 1587.10.21 | 1587.11.1 |
| Transylvania | 1590.12.14 | 1590.12.25 |
| Iceland | 1700.11.16 | 1700.11.28 |
| Italy | 1582.10.4 | 1582.10.15 |
| Latvia | 1918.2.1 | 1918.2.15 |
| Lithuania | 1918.2.1 | 1918.2.15 |
| The Netherlands | ||
| Holland, North Brabant | 1582.12.21 | 1583.1.1 |
| Gelderland, Zutphen | 1700.6.30 | 1700.7.12 |
| Utrecht, Overijssel | 1700.11.30 | 1700.12.12 |
| Friesland, Groningen | 1700.12.31 | 1701.01.12 |
| Drente | 1701.04.30 | 1701.05.12 |
| Norway | 1700.2.18 | 1700.3.1 |
| Poland | 1582.10.4 | 1582.10.15 |
| Silesia | 1584.1.12 | 1584.1.23 |
| Portugal | 1582.10.4 | 1582.10.15 |
| Romania | 1919.03.31 | 1919.04.14 |
| Russia | 1918.01.31 | 1918.02.14 |
| Spain | 1582.10.4 | 1582.10.15 |
| American Colonies | 1584 | 1584 |
| Sweden (final conversion -- see note) | 1753.2.17 | 1753.3.1 |
| Switzerland | ||
| Lucern, Uri, Schwyz, Zug, Freiburg, Solothurn | 1584.1.11 | 1584.1.22 |
| Wallis | 1655.2.28 | 1655.3.11 |
| Zürich, Bern, Basel, Schaffhouse, Geneva, Thurgovia | 1700.12.31 | 1701.1.12 |
| Appenzell, Glarus, St. Gallen | 1724 | 1724 |
| United States | ||
| British Colonies | 1752.9.2 | 1752.9.14 |
| Alaska | 1867.10.5 | 1867.10.18 |
| Yugoslavia | 1919.03.04 | 1919.03.18 |