How the date of Easter is set

Origin and history

Because the Gospels place the crucifixion and resurrection at the Jewish feast of Passover, which follows a lunar calendar, Easter has always moved from year to year. In the second century some Christians in Asia Minor, called Quartodecimans ('fourteeners'), kept the feast on the 14th of the Jewish month of Nisan, whatever day of the week it fell; others kept it on a Sunday. Irenaeus records that Polycarp, bishop of Smyrna, discussed the difference with Anicetus, bishop of Rome. The First Council of Nicaea in 325 aimed at a common date for all Christians: the first Sunday after the first full moon on or after the spring equinox. Working this out, a calculation called the computus, was so important that it was a main reason for the Gregorian calendar reform of 1582.

Customs

• In the West, Easter Sunday always falls between 22 March and 25 April.
• In England, the northern English churches adopted the Roman way of calculating Easter after the Synod of Whitby in 664, and Bede described the method in detail in 725.

How traditions differ

Catholic and Protestant churches use the Gregorian calendar to calculate Easter, and most Eastern Orthodox churches use the Julian calendar, so Orthodox Easter often falls one or more weeks later. In some places the churches agree on one date; on the Greek island of Syros, where Catholics and Orthodox live side by side, both keep the Orthodox date.

In the library

Works: Ecclesiastical History of the English People · The History of the Church

Great Lives: Bede · Irenaeus of Lyon · Constantine the Great

More in Eastertide

Easter · St George's Day · Ascension Day · Pentecost