Leap Year, George Washington and the Jewish Calendar

Imagine having your summer vacation in January, or Christmas in June. Seems unlikely, doesn’t it? But that’s exactly where we would be at today if Caesar had not adopted the changes to the “Julian” calendar when he added one day every fourth year to keep everything in order. Of course, we know it as leap year, and it is an accepted part of living, engendering such witticisms as, “If you’re born on February 29th then you don’t get to vote until you’re 72 years old!” Or, “If you marry on February 29th then you only have to buy the wife a gift every 4th year.” Right; you try it, and let me know how that works out for you.

I have always been fascinated by numbers, even when failing math in grammar school.(I was fascinated at how low my grades were.) Still later, while working as a grocery clerk, before the advent of the modern day cash register, I was further enamored of the precision of numbers in general. And, still later, as a Quartermaster in the Navy, and then as a qualified 3rd Mate aboard oil tankers, the absolute nature of the stars in their movements, hooked me on math forever. In that spirit I offer the following, and accepted, mathematical reasons for the need of a leap year.

In 46 BC, Julius Caesar was faced with the problem that the Roman calendar then in use had slipped 81 days. This was especially noticeable at the spring equinox, which was an agricultural benchmark affecting the planting of crops. Something needed to be done to correct the error. Caesar simply added 81 days to the calendar, and instituted the leap year, bringing all things back to their proper order; for a time.

The Julian calendar, which is the one in use from 46 BC until 1582 AD, was based upon 365.25 days for one journey around the sun. Now, this was pretty good shooting for 46 BC, but by the 16th Century advances in science, and navigation, had revealed the actual length of time to orbit the sun as being a bit shorter; 365.2422 days, which meant that we were now out of whack by 10 days, which was fouling up the date on which to observe Easter. In preparation for Easter of 1582, Pope Gregory XIII deleted 10 days for that year, which reset the clock, so to speak. That became known as the Gregorian calendar, which is what we still use today.

As time has gone by, even the Gregorian calendar has come up for correction. George Washington, the father of our country, was actually born on the 11th of February in 1732. His birthday was advanced by 11 days in 1752 when the colonies switched from the Julian calendar to the Gregorian calendar. I have never really been sure of why the colonies were using the older Julian calendar, so I will have to look into that. But poor George Washington, he seems destined to never have a permanent birthday, as we now celebrate his special day as a three day weekend, or President's Day, which gives him a “leap” in his birthday every year, rather than one in every four.

There are many different calendars in use around the world, each with its own version of Leap Year. My own religion, Judaism, makes use of the older Lunar calendar which requires a correction of almost 20 days, or so, making it a 13 month year. That month is named Adar I, or, the "lucky" month. It is neatly slipped in between the months of Shevat and Adar, giving the leap year a total of 385 days. The Jewish Leap Year is also known as the "Pregnant" year; "Shanah Me'uberet" in Hebrew; as it bulges with extra days. These leap years are distributed 7 times over a 19 year period, and occur during the 3rd, 6th, 8th, 11th, 14th, 17th, and 19th years of the cycle. This is known as the Metonic cycle and marks the moons return to the exact place, at the same longitude, with the same constellation in the sky. Moreover this occurs at the time when the moon is in the exact same phase as it was at the beginning of the cycle.

I don't know whether I'll post tomorrow, or not, what with it being Leap Year. It seems like a lot of trouble; that's why I'm posting this today. But knowing me, I'll probably post something anyway. Being compulsive kind of becomes a habit.