St. Patrick's Day vs. Easter

A few days ago Melissa looked at the calendar and realized that Easter is only 6 days after St. Patrick's day this year. The big question was "Which one should we decorate for?". I don't know that we even have a shamrock or a blarney stone, so Easter will win out easily :) It made me think though why Easter is celebrated on different days each year. It turns out that Easter is a moveable feast that isn't fixed on a Julian or Gregorian calendar but is determined on a lunisolar calendar, like the Hebrew calendar. Thank you wikipedia. The simple answer is Easter falls on the Sunday after the first full moon after the Spring equinox, which is March 21st. Boy, those geniuses at the Nicean council really knew how to make a holiday. Why not just pick the first Sunday of April? Anywho, this means that Easter can be as early as March 22nd or as late as April 25th. This year is the second earliest it could be, in 2011 it will be the second latest. The cycle of Easter dates repeats after exactly 5,700,000 years, with April 19 being the most common date, happening 220,400 times, or 3.9% compared to a mean for all dates of 162,857 times, or 2.9%. So there you have it, please celebrate accordingly.