When Europe switched to the Gregorian calendar, 1582–1923

Timeline

Layers

1582 · Spain, Portugal, Italy, Poland, France · 1583–1584 · Catholic Germany, Austria, Bohemia · 1585–1699 · Later adopters: Hungary, Prussia, Valais · 1700–1701 · Protestant Germany, Denmark, Dutch · 1702–1752 · Banat, St Gallen, Great Britain and Ireland · 1753 · Sweden and Finland · 1754–1915 · Last Swiss communes, Balkans, Baltic · 1916–1918 · Bulgaria, Ottoman Empire, Russia · 1919–1923 · Romania, Serbia, Montenegro, Greece · 1700–1712 · Sweden's own calendar (1 day off Julian)

Events

• 6 Mar 1582, Gregory XIII signs the bull Inter gravissimas: Dated 24 February 1582 at Tusculum (Frascati), where the pope spent the summer at Villa Mondragone. Ten days are to vanish in October, and three leap days are dropped every 400 years from then on.
• 15 Oct 1582, Thursday 4 October is followed by Friday 15 October: The Papal States, most of Italy, Spain, Portugal and Poland–Lithuania skip ten days on the day the bull set. Everyone else takes months, years or centuries.
• 4 Jun 1584, Calendar riot in Augsburg: In a city split between Catholics and Lutherans, the council tried to expel a Lutheran preacher who told his flock to keep Ascension by the old calendar. A crowd freed him and stormed the armoury; the new calendar stayed.
• 20 Nov 1594, Groningen goes back to the Julian calendar: After Maurice of Nassau took the city for the Dutch Republic, Saturday 19 November (new style) was followed by Sunday 10 November (old style). Groningen switched again in January 1701.
• 3 May 1616, Cervantes and Shakespeare die on '23 April 1616': Cervantes died in Gregorian Madrid on 22 April and was buried on the 23rd; Shakespeare died on 23 April in Julian England, which was 3 May in Spain. The famous shared date is about ten days apart.
• 11 Mar 1700, Protestant Germany and Denmark skip eleven days: After a vote of the Protestant estates at the Diet in Regensburg, Sunday 18 February 1700 was followed by Monday 1 March. Their 'Improved Calendar' still worked out Easter its own way until 1776.
• 12 Mar 1712, Sweden's 30 February: Sweden had left out the leap day of 1700, planning to drift into step with the Gregorian calendar, and then gave up. To get back to the Julian calendar, February 1712 had 30 days, the only time in history.
• 14 Sep 1752, Britain: Wednesday 2 September is followed by Thursday 14 September: The Calendar (New Style) Act 1750 brings Britain, Ireland and the colonies into line. The year had already begun on 1 January 1752 instead of 25 March.
• 17 Apr 1754, 'Give us our eleven days': an election joke, not a riot: Tories used the slogan against a Whig candidate whose father had steered the reform, and Hogarth painted it on a placard in An Election Entertainment. Historians have found no record of the calendar riots of later legend.
• 5 Oct 1793, France leaves the Gregorian calendar for a republican one: Twelve months of 30 days, ten-day weeks, years counted from the Republic of September 1792. Napoleon brought the Gregorian calendar back on 1 January 1806.
• 7 Nov 1917, The 'October' Revolution happens in November: The Bolsheviks took power on 25 October by Russia's Julian calendar, which was 7 November everywhere west of it. Their government switched on 14 February 1918.
• 1 Mar 1923, Greece, the last in Europe: 15 February is followed by 1 March: Greece moves its civil calendar 13 days forward. Mount Athos and the church kept the Julian reckoning; Turkey adopted Gregorian year numbers in 1926.