The Gregorian calendar took 341 years to reach Greece
On this day · 15 October 1582
The new calendar took effect on 15 October 1582 in Catholic Europe. Others held out for centuries — and Flanders lost Christmas along the way.
The Gregorian calendar took effect on Friday, 15 October 1582, the day after Thursday 4 October in Spain, Portugal, Poland and most of Italy, but the rest of the world joined over the following 341 years: Greece did not switch until 1923.
Pope Gregory XIII chose October because it was a month with few church holidays to disrupt. Catholic Europe followed quickly but not in step, and Protestant states, which rejected papal authority, held out longer:
- December 1582: France and the Spanish Netherlands change. In Flanders and Hainaut 21 December is followed directly by 1 January 1583, so Christmas 1582 never happened there.
- 1583 to 1610: Austria (1583), Bohemia and Moravia (January 1584), Hungary (1587) and Prussia (1610).
- 1700: Denmark and the remaining Protestant Dutch provinces switch.
- 1712: Sweden, trying to convert gradually by skipping leap days, gets confused and ends up with a 30 February.
- 1752: Britain drops eleven days.
- 1872 to 1923: Japan in 1872, China in 1912, then Bulgaria, Russia, Romania and Greece.
Each delay made the jump bigger, because the Julian calendar kept every century year as a leap year. After 5 Oct 1582 you add 10 days to a Julian date; after 28 Feb 1700, 11; after 28 Feb 1800, 12; after 28 Feb 1900, 13. Britain, in 1752, had to drop eleven.
The last adopters were largely outside Western Christianity. Russia’s late switch is why the October Revolution of 1917 is now commemorated in November. For historians the staggered rollout is a trap: a reply written in England could carry an earlier date than the French letter it answered.
Sources & references
3 referencesWell-established. Corroborated by 3 independent sources.
