Both Passover and Easter use a lunar calendar.
The reason why Easter comes out on "The first Sunday after the first fourteenth day of the moon that is on or after March 21" is because 99% of the time - that is the Sunday during Passover (Passover starts at sundown of the end of the 14th day-start of the 15th day of the month of Nissan on the Hebrew Calendar).
Now the question you will have is: why is Passover a month from now...
The Hebrew calendar has a set formula to calculate leap years - (certain holidays have to occur during certain seasons... such as Passover during Spring) In order to properly make up the days - and entire month is added 7 times in 19 years. (It's explained fairly well here: http://en.wikipedia.org/wiki/Hebrew_...ar#Leap_months
). So this year - a month has been added.
Have i made it more confusing?
(o and the bring things full circle: the name Easter
is derived from the Greek name, Pascha
which is itself derived from Pesach
, the actual Hebrew name for Passover.)
I'd love to see this in HD someday