In a letter to Pope Francis, the patriarch of the Coptic Orthodox Church Tawadros II has proposed making one date for Easter celebrations for all Christian Churches.
Differences in Easter dates are based on differences between the Julian calendar, which eastern churches follow, and the Gregorian calendar of western churches.
Finding one Easter date for both western and eastern churches is said to be an urgent matter.
This is particularly so in Christian communities in North Africa and the Middle East, where Easter is observed on different dates.
In 2014, the western and eastern Easter dates fell on the same day, April 20.
The next time the dates coincide will be in 2017 and then in 2034.
A representative of the Coptic Church has been invited to the next assembly of the synod of bishops, in October.