Today as we celebrated Easter at White Fields Church in Longmont, Colorado, we had a special greetings sent in from some of the missionaries we support around the world, including several in Ukraine.
Here’s the video of the Easter service, which includes the greetings from those missionaries:
Some of the missionaries in Ukraine mentioned that their country celebrates Easter a week later than we do in the United States, leading some people to ask why that is.
Council of Nicea (325 AD): Setting a Common Date for Easter
The First Ecumenical Council of Christin leaders around the world as held in 325 AD and is known as the Council of Nicea.
Prior to Nicea, churches in different parts of the world celebrated Easter on different Sundays of the year. In order to bring unity, council members created a formula to would calculate the date for Easter for all churches around the world: the first Sunday after the first full moon which follows the vernal equinox, after the Jewish Passover.
To avoid confusion, it determined that the vernal equinox was on March 21. This system guaranteed that all churches around the world celebrated Easter on the same day.
The Great Schism and the Introduction of the Georgian Calendar
In 1054 the Eastern and Western churches split. The division was for theological, cultural, and political reasons. Shortly after this, Pope Gregory VIII introduced the Gregorian calendar, whereas the Eastern Empire continued with the Julian calendar, which had been used since the time of Julius Caesar.
The reason for the introduction of the Gregorian calendar was the realization that the Julian calendar was discovered to be 11 minutes too long, which, though not much, led to the spring equinox no longer being on March 21 by that time. The Gregorian calendar sought to bring correction to this issue, whereas the Eastern Empire (and its churches) continued with the Julian calendar despite the fact that according to it, the vernal equinox was no longer on March 21.
By using two different calendar systems, the vernal equinox now fell on March 21 under the Gregorian calendar and April 3 on the Julian calendar. The two empires (and their churches), as a result, began celebrating Easter on two different days, though on occasion Easter date does still fall on the same day for both calendars (e.g. in 2017 and next in 2025).
As for the question of why the date of Easter changes every year, see: Easter Math: How Does It Add Up?