Today’s Lebanon Democrat carries a story claiming that Tennesseans should “thank a sixteenth century pope” for an extra day’s grace on property taxes this year.

Last-minute Tennessee taxpayers will get a little bit of help this year from an unlikely source – a 16th-century pope.

Property taxes usually come due on Feb. 28, but with 2008 being a leap year, that deadline is pushed back a day to Feb. 29, the day added to the calendar every four years, as the result of a 1582 decree by Pope Gregory XIII, when he instituted the calendar that bears his name.

While its nice to see a daily newspaper acknowledging that everything isn’t MTV, Youtube, and current events, it would be even nicer if they’d spend 10 minutes using the internet to do some elementary fact-checking. Pope Gregory XIII is not responsible for giving us the practice of adding a leap day in leap years. The author of that innovation was Julius Caesar.

The Julian calendar was a significant reform instituted by the Julius Caesar in 46 BC. Julius had spent a year in Egypt and hadn’t wasted ALL his time with Cleopatra. The Egyptian astronomers demonstrated to him, convincingly, that the calendar year was actually 365.25 days long. It was Julius’ idea to regularize this observation into a calendar that was 365 days long and added one day every four years.

Julius got it almost right. The calendar year is almost 365.25 days long. Its actually 365.2425 days long. That slight difference accumulated over time under the Julian calendar, and by 1582, the dates of the equinoxes and solstices had shifted by 10 days. This was especially troubling to the church when it came time each year to calculate the date for Easter. So Pope Gregory instituted a calendar reform in 1582 that dropped 3 leap days every 400 years. Under the Gregorian Calendar, century years are NOT leap years unless they are divisible by 400. And to correct the drift of the calendar in the 1600 years from Julius Caesar to Pope Gregory XIII, the Church decreed that in 1582, October 4th would be followed by October 15th.

Protestant countries thought this was a popish plot and refused to go along – for about 170 years. Britain and the British Empire finally adopted calendar reform by an act of Parliament in 1750. Parliament gave everyone two years to prepare for the adjustment. By the New Style Act of 1750, Wednesday September 2, 1752 was followed by Thursday, September 14, 1752. George Washington (and many others) adjusted the date on which they celebrated their birthdays, in order to accurately reflect when they really were celebrating the anniversary of their birth. Washington was born on February 11th, 1732. When the calendar was adjusted in 1752, he adjusted his birthday 11 days as well and ever after celebrated it on February 22.

Russia, being neither Roman Catholic nor Protestant, wanted nothing to do with such shenanigans. The Czars were never persuaded. It took the Russian Revolution and a communist dictatorship to reform the calendar in Russia. Wednesday January 31, 1918 was followed by Thursday, February 14, 1918.

Historians of the 17th century & 18th centuries, when trying to synchronize dates and correspondence between various catholic and protestant countries have been known to go mad.

Irresistible footnote: The “October Revolution” in Russia occurred on October 25, 1917 – in Russia. It was actually November 5, 1917 everywhere else in Europe.

But don’t thank the Pope for an extra day before your taxes are due this year. Thank Julius Caesar.

– Rob Shearer
Publisher, Greenleaf Press
Director, Schaeffer Study Center