What day is it again? On September 14, 1752, Great Britain finally adopted the Gregorian calendar, adjusting the date in such a way that the previous 11 days were skipped entirely (the day before this was actually September 2).
The Gregorian calendar wasn’t exactly a new invention. It was introduced in February 1582 by Pope Gregory XIII and was adopted later that year by a handful of countries, all Catholic. Protestant countries, like England, were less eager to switch their calendars around just so they could celebrate Easter on the date the Catholic Church liked best. Never mind that the old calendars had proven to be inaccurate in their measurement of the time between vernal equinoxes. The Julian calendar believed the time between the equinoxes was 365.25 days, but in reality, it’s about 11 minutes shorter. That doesn’t sound like such a big deal until you reckon it out over hundreds of years. By the time the Gregorian calendar was approved in the 16th century, Gregory had to drop 10 days right off the calendar just to bring it back in line with the seasons.
Spain, Portugal, the Polish-Lithuanian Commonwealth, most of Italy, the Southern Netherlands, and the Dutch provinces of Brabant, Zeeland, and the Staten-Generaal adopted the new calendar in 1582, with the provinces of the Southern Netherlands and Holland following suit in early 1583. Most Protestants, however, were suspicious of the new calendar and believed it was part of a plot to return them to the Catholic fold (apparently they scared easily). Catholic rebels in Ireland adopted it as a sort of “F you” to England.
Things went along like this for a while, but then Denmark adopted the solar portion of the calendar (but not the lunar portion, for some odd reason) in March 1700. The rest of the Dutch Republic fell in line in July 1700, and just over 50 years later Britain adopted it throughout its entire empire. It wasn’t the last country to adopt it—not by a long shot. Most of Eastern Europe clung to the old Julian calendar until World War I and the Russian Revolution. Greece finally made the switch in 1923, becoming the last European country to do so, and Turkey adopted the new calendar in 1926.