Gregorian Calendar

All of the Political Graveyard date pages, from January 1, 1701, to December 31, 2050, are dates of the Gregorian calendar. However, other calendars were in use for portions of this era, and the alternate dates are listed.

The Gregorian calendar, now in use almost throughout the world, was introduced by Pope Gregory XIII in 1582 as a reform of the pre-existing Julian calendar.

Under both the Julian and Gregorian calendars, a normal or common year has 365 days. Every year divisible by four is a "leap year", with an extra day added to February, for a total of 366 days. Across each four-year period, the average year is 365.25 days long.

The trouble was that, to coordinate the calendar year with the position of the sun — that is, with the seasons — the average year needed to be 11 minutes shorter.

Pope Gregory's solution was to eliminate three leap years out of each 400. Years divisible by 100, but not by 400, such as 1700, 1800, and 1900, are not leap years under the Gregorian calendar.

Different countries and regions switched to the new calendar at different times. France and Spain did so in the 1500s, so their New World colonies had the Gregorian calendar from the beginning. The British Empire and its colonies kept the Julian calendar until 1752. Russia, Greece, and other Orthodox Christian nations didn't adopt the Gregorian calendar until the early 1900s.

Changing from the "old" (Julian) to the "new" (Gregorian) calendar required skipping a number of days: 10 days if the change was made in the 1500s or 1600s, 11 days in the 1700s, 12 days in the 1800s, and 13 days in the 1900s.

In the English-speaking (British) world, the last Julian day, Wednesday, September 2, 1752, was immediately followed by the first Gregorian day, Thursday, September 14, 1752.

That was not the only change. Starting with January 1, 1752, they also changed when each year started.

Under the English Julian calendar, the beginning of the year was March 25. That meant the last seven days of March would be in a different year than the first part. For example, the last day of 1731 was March 24, 1731, immediately followed by the first day of 1732: March 25, 1732.

The confusion was intensified when Scotland, in 1600, changed its year to January 1st through December 31. So for 12 weeks every year, for more than a century and a half, Scotland was a year ahead of England.

During that period, in an effort to avoid ambiguity, English dates from January 1st to March 24th were customarily written with both years, such as "February 11, 1731/32".

Alaska

Alaska was part of Russia from 1784 to 1867. Russia (and hence Alaska) was on the Julian calendar during that time. Alaska was also on Russia's side of the International Date Line. That is, in the middle of the day, the date in Sitka, Alaska, was the same as the date in St. Petersburg.

When Alaska was sold to the United States in 1867, it crossed the International Date Line and switched to the Gregorian calendar. So, in Alaska, Friday, October 6, 1867, was immediately followed by Friday, Ocober 18, 1867.

Political Graveyard date pages during 1784-1867 show the date in Russian Alaska, but using English names for days and months.

French Republican Calendar

Following the overthrow of the monarchy in France, the revolutionaries desired to rid the country of the trappings of religion and the old regime. The metric system of weights and measures was invented at this time, based on simple, rational multiples of ten.

To replace the Gregorian calendar, a new calendar was also created, with uniform 30-day months, 10-day weeks, 10-hour days, and 100-minute hours. The years were numbered with Roman numerals.

Most fascinating of all, to replace the Catholic saints' days, each individual day of the year had a different name. It was called the Rural Calendar, as the names were drawn from rural life, so representing farm tools, crops, herbs, trees, animals, and minerals.

This new calendar was used in France, and in French colonies around the world for about 12 years.

Political Graveyard date pages during 1793 to 1805 show the French Republican date, including the Rural Calendar day name.

Jewish or Hebrew calendar

The Hebrew calendar, codified in the 12th century CE, numbers the years since the assumed Biblical year of creation.

A common year is twelve lunar months, which comes to about 354 days; to make up the difference, some years have thirteen months.

All of the day pages in Political Graveyard show the Jewish or Hebrew dates for that day.

Hebrew days begin and end with sunset. Accordingly, on each day page, two dates are given, corresponding to the portions of the Gregorian day before and after sunset.

Further Reading

• Julian calendar
• Gregorian calendar
• Adoption of the Gregorian calendar
• British Calendar Act of 1751
• Old Style and New Style dates
• Alaska Day
• French Republican calendar
• Hebrew calendar.