Why is Orthodox Easter a Different Date?

Q. Why don’t Orthodox Christians celebrate Easter on the same day as Catholics and Protestants?

A. The day designated for annually celebrating our Lord’s resurrection varied within the early Church, a situation that sometimes led to controversy. So the fathers of the First Ecumenical Council, at Nicaea (A. D. 325), standardized the method for determining its date.

Though Christmas always occurs on a set date (December 25), Easter was established as a moveable feast, dependent on the shifting relations each year between the cycles of the moon and the sun. The Nicene fathers declared that Easter would fall on the first Sunday after the first full moon to occur after the vernal equinox. The vernal equinox is the time each spring when the sun crosses the plane of the earth’s equator, so that night and day are of approximately equal length all over the world. It usually falls on March 21, so Easter never occurs before March 22 or after April 25. We should note that this not a precise statement of the actual Church rules for determining the date. The full moon involved in calculation is not the astronomical full moon, but rather an “ecclesiastical moon” determined from rather complicated tables developed by the Church. Nevertheless, the ecclesiastical moon keeps in step, more or le