Amy Pollard, age 14, of Springfield, I11., for her question:

WHY DOES EASTER SUNDAY'S DATE CHANGE?

This year Easter falls on Sunday, April 3, while last year the date for the Christian holiday was Sunday, April 19. Easter can fall on any Sunday between March 22 and April 25 because of a schedule worked out in A.D. 325.

Easter is Christianity's oldest sad most important holiday. It commemorates the resurrection of Jesus Christ and it replaced two other events held earlier: the pagan festival of Eostur Monath and the Jewish Passover.

Back in the second century, the Roman church's Pope Victor I decreed that the Christian churches observe Easter on Sunday, the first day of the week, when Jesus Christ rose.

The churches in the Roman provinces of Asia refused and continued to celebrate Easter on the 14th day of the Jewish month Nisan, the same day as Passover, whether 1t fell on Sunday or not. The Pope excommunicated those churches for not following the new order.

Then at the Council of Nicaea meeting in A.D. 325, the Roman emperor Constantine backed the Pope. The date for Easter was set according to the Gregorian calendar as the first Sunday following the full moon on or after the vernal equinox, March 21. This schedule made it possible for Easter Sunday to fall anywhere between March 22 and April 25.

All of the Western Christian churches follow the same schedule, but Eastern Orthodox churches use the Julian calendar and celebrate Easter on the first Sunday after the Jewish Passover. Easter can be celebrated in Eastern and Western churches as much as five weeks apart.

To get ready for the important Easter celebration, Christian churches in all parts of the world have a 40 day period of preparation before the holiday. This period is called Lent. The 40 day period was set because Jesus had wandered in the wilderness for 40 days before he started his ministry, and because it has been estimated that he spent 40 hours in the tomb. Lent starts with a day called Ash Wednesday.