Easter day in 2008 is March 23. Can you remember it before? Well, that’s your date in Western churches. Eastern (Orthodox) churches this year actually celebrate Easter day more than a month later, on April 27. How is Easter day resolved?

The date of Easter is calculated by the intricate union of different calendar systems. We can think of these two calendars because of the early history of Cain and Abel. Abel, you may remember, had the flocks, and Cain had the crops. If you are an Abel type, you will hunt, fish, and tend your flock at night. This means that the moon will be important to you with its lunar cycle of 29 and a half days. The moonlight and the tides will be important to you. On the other hand, if you are a Cain type, a tiller of the land and cultivator of crops, then the solar cycle and the seasons will be more important to you. The calculation of the date of Easter day originates from the combination of these solar and lunar calendars.

jewish passover

The Jewish calendar centers on the moon. There are twelve lunar months. Some years an extra month is added to keep the year in line with the solar year. The month begins with a new moon, and a full moon, in the middle of the month, is the obvious time for extended parties and festivals. There is more light at night! Passover (Pesach) is the celebration of being led by Moses to deliverance from slavery in Egypt. This is celebrated on the first full moon after the vernal equinox (northern spring). In the Bible this is 14 Abib (Leviticus 23:5). This Passover celebration is commanded in the Bible to be a “perpetual ordinance” (Exodus 12:14).

There is some confusion between the so-called Synoptic Gospels (Matthew, Mark, Luke) and the Gospel of John to determine the exact relationship between Easter and the death and resurrection of Christ. Easter Day, the celebration of the resurrection of Christ, has always had a particular connection with Easter.

The Council of Nicaea

Some Christians in the early church celebrated Easter on the same date as the Jewish Passover, whichever day of the week it fell on. These were called quartodecimans (from the Latin: quarta tenth, meaning “fourteen” – a reference to the day in the Jewish month). Other Christians in the early church always celebrated Easter on the Sunday following the Jewish Passover. When Christianity essentially became the religion of the Roman Empire in the fourth century, Emperor Constantine demanded that the church get together and decide when Easter would be celebrated. The bishops of the church met at Nicaea in AD 325. They decided that Easter would always be a Sunday. They communicated this decision to the entire church and gave the bishop of Alexandria the privilege of announcing the date on which Easter would fall each year.

Part 2 will explain why the East and West ended up with different dates for Easter.