In 325CE the Council of Nicaea established that Easter would be held on the first Sunday after the first full moon occurring on or after the vernal equinox. From that point forward, the Easter date depended on the ecclesiastical approximation of March 21 for the vernal equinox. Easter is delayed by 1 week if the full moon is on Sunday, which decreases the chances of it falling on the same day as the Jewish Passover. The council’s ruling is contrary to the Quartodecimans, a group of Christians who celebrated Easter on the day of the full moon, 14 days into the month.
Not all Christian churches observe Easter according the Gregorian calendar. Some churches still observe Easter under the Julian calendar. The Gregorian calendar was created because the Julian calendar was slightly too long. With the Julian calendar, the equinox date moved towards the earlier dates of March and further away from the Easter. Therefore, the introduction of the Gregorian calendar allowed for a realignment with the equinox.
In the Gregorian calendar, Easter falls on a Sunday between March 22 and April 25 from 1753 to 2400. In the Julian calendar, used by some eastern or Orthodox churches, Easter also falls on a Sunday from March 22 to April 25, which in the Gregorian calendar are from April 3 to May 10 from 1753 to 2400.
There have been a number of suggested reforms for the Easter date. For example, in 1997 the World Council of Churches proposed a reform of the Easter calculation to replace an equation-based method of calculating Easter with direct astronomical observation. This would have solved the Easter date difference between churches that observe the Gregorian calendar and those that observe the Julian calendar. The reform was proposed to be implemented in 2001, but it is not yet adopted.
Another example of a proposed reform occurred in the United Kingdom, where the Easter Act 1928 was established to allow the Easter date to be fixed as the first Sunday after the second Saturday in April. However, this law was not implemented, although it remains on the UK Statute Law Database.
If you celebrate Easter, may you have a peaceful and happy celebration!
This post is part of the Skywatch Friday meme,
and also part of the Friday Photo Journal.