Mathematics Throughout History

Math and Calendars in History

What are some interesting facts about the Julian and Gregorian calendars?

An interesting fact about the Julian calendar is that it designates every fourth year as a leap year, a practice that was first introduced by King Ptolemy III of Egypt in 238 B.C.E. A quirk about the Gregorian calendar is that the longest time between two leap years is eight years. The last time such a stretch was seen was between 1896 and 1904; it will happen again between 2096 and 2104.

