Why does Easter change every year, when dates like Christmas are fixed? The early church grappled with how Easter is determined, and the processes for scheduling the holiday weren't fully set in stone until the 16th century. On top of that, the dates of Easter used by most Western Christian churches don't match how most Eastern Christian churches determine the dates for the sacred day.
In the early days of Christianity, different groups of Christians celebrated Easter on different dates. All agreed that Jesus Christ was crucified and that Easter celebrated his resurrection a few days later. But early Christians in Asia Minor (now Turkey) observed the date of his crucifixion on the first day of the Jewish festival of Passover — "Pesach" in Hebrew — which celebrates the liberation of the Jewish people described in the biblical Book of Exodus after they escaped being slaves in Egypt.
