Why are western Easter and orthdox Easter different?

Answer 1

Easter is calculated to follow the Jewish feast of Passover. The Jews use the Jewish calendar to calculate when Passover should occur.

Catholics and most Protestants use the new Gregorian calendar decreed by Pope Gregory XIII in 1582 to calculate the date of Easter.

The Orthodox Church uses the old Julian calendar introduced in 46 B.C.E. by Julius Caesar.

As long as you celebrate the Resurrection of Jesus Christ, does the exact date really matter?

Answer 2

Because the western churches use the Gregorian calendar and the eastern orthodox churches use the Julian calendar. Easter is always celebrated on the first Sunday following the first full moon after the beginning of Spring. Because the two calenders have different dates for the beginning of Spring the dates of Easter differ. According to the Gregorian calendar Spring begins on March 21, so western Easter can be between March 22 and April 25 (both dates included).