Sunday, February 29, 2004

Leap This

Leap Day! Leap Day! Leap Day!

It's not often I get to post on a leap day. Might be awhile for the next one too. Here's some history on the leap day.

Currently the United States uses the Gregorian calendar. The Gregorian system named after the 16th century Pope Gregory XIII is actually a modification to what was the Julian calendar, a system ordered by the Roman emperor Julius Caesar in 46 B.C. where the leap day system was instituted. The addition of the leap day was to correct for the not-so perfect revolution of our beloved planet around our equally important, and the only star that can be found in this solar system, known as the sun. According to the Julian calendar, the length of one standard year is given as a trip that takes 365.25 days. That .25 is 1/4th of a day so every four years, we get synced back up with our actual location in the solar system by adding a day to our calendar.

However, the 365.25 figure is actually a rounded off value. It doesn't take the Earth exactly 365 and 1/4th day to get around the sun - it's more like 365.2422.

This is where Pope Greg comes in to tighten the formula up with his personal tweak. Since 365.2422 is a little less than 365.25, things are still a wee bit out of whack even after each leap day. Everyone knows the leap day comes every four years but to keep things close to 365.2422 there are times when the leap day is not used.

Here are the rules:

* A leap day occurs every four years, the year being evenly divided by four. 2004 is a leap year.

* Except every 100 years, the year being evenly divided by 100. No leap day on those years to occur. 1900 was not a leap

* Exception to that exception is every 400 years, the year being evenly divided by 400, on those century dates, go ahead
and have the leap day anyway. 2000 was a leap year. So was 1600; however, 1700, 1800 and 1900 were not.

Even after all of those adjustments, we are still off several seconds so every once in awhile, the U.S. Government will declare on behalf of our scientists to have what's called a leap second, where an extra second is added to some arbitrary day to get us back on course. The inaccuracy without the leap second is not enough to mess up our seasons. It's not like our farmers will try planting corn in December, but in this technical day and age and the keeping of the atomic clock. it has become important to be more anal about the time.

I don't think the Mooninites had so much trouble calculating their calendar. It's probably that they wouldn't care.