What were the shortest and longest months and years? Let’s restrict this to official calendars as used in some country or countries sometime in history.
I’ve been researching this and the shortest month I’ve found is either 15 days or 3 days[sup]1[/sup] and the longest year is 445 days. Not sure about the shortest year or the longest month, although possibly 34 days for the latter. Anyone have any better info?
[sup]1[/sup] There was a brief use of the French Republican Calendar during the Paris Commune which ended on 3 Prairial An LXXIX, making that month last only 3 days. I don’t think this should count though.
Look at when the Julian calendar changed to the Gregorian calendar. For those countries that switched in 1582 only ten days got dropped. When Turkey finally changed in 1926, the days that got dropped was already up to 13. In the USA we lost 11 days when we switched in 1752.
What is significant with the USA change is we celebrate Washington’s Birthday on February 22. He was actually born on February 11, 1732 (OS).
February 11, 1731 (OS), and February 22, 1732 (NS). When Britain and its colonies made the change to the Gregorian Calendar in 1752, they also adopted the convention of starting the year on January 1 rather than March 25, so dates before March 25 in old style came out a year later in new style:
Japan uses era names so when Emperor Hirohito died on Jan 7th, 1989 the year Showa 64 immediately ended and the year Heisei 1 began. The same think will happen when Emperor Akihito dies.
Yes, I know. That’s where I got the 15 day shortest month. Actually, two of them. Feb 1918 in Russia and Feb 1923 in Greece were both shortened by 13 days, making them 15 days long.
But I thought of an even shorter one since I posted the OP. Napoleon abolished the French Republican calendar on 1 Jan 1806. That made Nivôse an XIV only 10 days long. And made the year XIV only 100 days long.
OK, I disallowed the Paris Commune use of the Republican Calendar, so how is this different? The Commune calendar ended because the Commune ended. Let’s set the rule that the beginning and end of the month/year in question, including any days added or removed, must be under the control of a single authority.
So the year Showa 69 was only 7 days long? Ditto for January Showa 69? If so, I think we have a couple winners.
So now for the longest. The 445 day year I cited in the OP was 46 BC, when Caesar added two additional intercalary months to make up for ones missed due to war. These two months totaled 67 days, although we don’t have specifics about how they were apportioned between them or even what they called the months. But even if they split them as evenly as they could, the longer of the two must have been 34 days. Could have been longer, though. (BTW, the year after that was the start of the Julian Calendar, so there were no more intercalary months.)
BUT no one actually considers that to mean that Showa 64 is not Heisei 1.
They consider that Showa 64 IS Heisei 1, being the year 1989 CE / AD/what those westerners invented…