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Fascinating Historical Calendar Fun Facts
Our modern calendar (the Gregorian calendar) took thousands of years of astronomical observations and political reformations to develop. Here is how modern calendar systems were formed:
1. February Was Originally the Last Month
In the early Roman calendar (created around 750 BCE), the year began in March and lasted 10 months. January and February were added later at the end of the year. Because February was the final month, leftover missing days were subtracted from it, leaving it shorter than other months.
2. Why Do Months Have Different Days?
Under Julius Caesar's calendar reform, odd months had 31 days and even months had 30 days (except February). Later, Emperor Augustus renamed the month of Sextilis to August and added an extra day to it so it equaled Julius Caesar's month (July).
3. The 3 Leap Year Rules
Earth orbits the sun in roughly $365.2422$ days. To sync our clocks, leap years occur every 4 years. However, century years (like 1900) are not leap years unless they are divisible by 400 (e.g., 2000 was a leap year, but 2100 will not be).
4. September 1752 Lost 11 Days
When Britain and its American colonies adopted the Gregorian calendar in September 1752, they had to skip 11 days to correct solar drift. Citizens went to sleep on September 2, 1752, and woke up the next morning on September 14, 1752!