In 1582, the past 10 days did not exist. That statement might appear to be from a science fiction novel, rather than a comment on history, but it is not. At the time, for the previous 1600 years, Europe had operated under the calendar promulgated by Julius Caesar on January 1, 46 B.C., but that calendar was not sufficiently accurate as it miscalculated the length of the solar year by 11 minutes.
As a consequence, over the centuries the calendar fell out of sync with the seasons. Easter was celebrated on March 21, but papal astronomers—led by the mathematician, Aloysius Lilius—advised Pope Gregory XIII that the calendar would move the feast further as the centuries progressed.
Lilius died in 1576, and his brother, Antonio, carried on the work with the calendar reform commission, presenting their findings to Pope Gregory XIII, who promulgated the reform to take effect on October 15, 1582. The new version eliminated 10 days, and it was to take effect at midnight on what became the night of October 4-15, 1582. The pope ordered all Catholic clergy to adopt it, and he urged Catholic sovereigns to do the same.
The Protestant and Orthodox countries did not accept the reform, continuing to follow the Julian Calendar. Many saw the change as a papal attempt to take over their liturgies. Britain did not adopt the calendar until 1752, significantly when George Washington was 20 years old. By the Julian Calendar, in force in the Colony of Virginia at the time when he had been born here in the Northern Neck, the date was February 11, 1732, but that date became February 22 in the Gregorian calculation after its adoption. Washington never accepted the change, and he continued to celebrate his birthday on the 11th for the rest of his life.
The Protestant states of Germany adopted the new calendar in 1700, although the Catholic states had followed the papal directive since its promulgation. Given at the time Germany consisted of 360 separate states, the system must have been quite confusing in matters of trade and commerce.
The Russian Empire remained Julian, calendar-wise, until after the Bolshevik Revolution in 1917. In that regard, the two revolutions of 1917 are named for the months in which they occurred. The February Revolution that replaced the Tsar with the Provisional Government occurred in March, and the Bolshevik seizure of power on October 25th actually took place on November 7th.
Tom Clancy’s 1984 novel, The Hunt for Red October—which in 1990 was the basis for the movie of the same name starring Sean Connery—was a spy-thriller about the search for a submarine named Red October, the name coming from the Julian calendar dare for the Bolshevik Revolution.
The common practice in denoting a date in areas still under the Julian calendar is to follow the numerical designation with a parenthetical (o.s.) or (n.s.), indicating Old Style or New Style. When written out, capitalization is followed, but not when used parenthetically. Although predominantly Orthodox countries have adopted the Gregorian Calendar, the Orthodox churches have not, thus their Easter celebration is on a date different from that of Catholic and Protestant churches.
To rectify the discrepancy in the Julian calculation, the Gregorian Calendar altered the Julian practice of the inclusion of a leap year every four years, which had not been accurate in measuring solar time. The new version has a leap year every four years except in years evenly divisible by 400. The year 2000 was the first such year since 1600 that was a leap year, and the next will be in 2400. 1700, 1800 and 1900 were not leap years as they were not divisible by 400.
As the old saying goes; “Time marches on!” Happy Calendar Day to all my fellow time-counters!