In Early Christianity, the controversy had risen on the correct date for Easter and even today it is a point of debate whether the date should be reformed. Ecclesiastical history has documented three distinct phases based on this Easter Controversy; here the first, second and third phases are discussed stating the date and the nature of the controversies -
In the first phase controversy, according to Bible, Easter was supposed to be celebrated on a week day. However, according to the older tradition, the Jews sacrifice lamb on the fourteenth day of moon and that day should be considered as feast of life-giving pasch. The fast must end on that very day and it can be any day of the week. Other churches that follow Apostolic tradition terminate their paschal fast on the day of Resurrection of their Lord. According to them Resurrection of the Saviour must be celebrated on Sunday.
There was a debate on whether to celebrate Easter on Sunday or on 14th day of moon. Those who follow Jews were known as Quartodecimans. After Pope Victor took strong measures, the population of Quartodecimans gradually decreased.Second Phase of Easter Controversy –
The second phase of Easter Controversy revolves round the Council of Nicaea (A.D. 325). According to them, the Easter festival should be always held on a Sunday, and it might not concur with a specific phase of moon, that may happen on any day of week. A difference in opinion occurred when Sunday is determined for celebration of Easter festival.
The Syrian Christians held Easter festival on the Sunday after the Pasch of the Jews is completed. Conversely the Christians of Alexandria and rest of the Roman Empire pay no interest to the Jews and calculate the Easter time by themselves. Thus the date of Easter as kept by Jews does not match with the date as kept by Christians of Antioch and Alexandria. The Jews were depended on Antioch who used to adopt random methods of interpolating embolismic months before celebrating Nisan, the initial spring month, on the 14th day when the paschal lamb was slaughtered. This practice was gradually neglected. The Alexandrians consider Sunday for celebrating Easter day but according to them the day must occur after vernal equinox and it should be identified with the 21st day of March as per Julian calendar.
The Council of Nicaea, did not consider Roman and Alexandrian calculation as standard and the council ruled out certain points concerning Easter festival celebration.
The ruling of Council of Nicaea was not successful enough to eradicate all difficulties and could not win universal acceptance from the Syrians at once. But afterwards the Syrians co-operate with the Council and help them to carry in to effect the Council of Nicaea’s decision.
During the time of St. Gregory, when the Roman missionaries came to England, they found Christians of Britain who are representatives of Christianity that was introduced in Britain during the time of Roman occupation; still stick to the ancient system of Eastern computation which Rome had already discarded. The Irish and British Christians celebrated Easter festival on Sunday, so they were not Quartodecimans. They are believed to have observed eighty-four cycle and not five hundred thirty two cycles of Victorious as mentioned in Gaul. As per latest investigator of the question, it is very difficult to decide upon what system they used to follow and inclines that they took help from Asia Minor for deriving rule to determine the Easter date.
The Easter is calculated depending on the moon which travels with regular motion of the real moon, which is basically the moon of the calendar not the one we see in heaven. According to the rule, Easter Sunday is considered first Sunday that occurs after first full moon that is after the first 14th day of the moon following 21st day of March. The whole world approves this rule. Therefore, the earliest possible day for celebrating Easter is March 22 and latest April 25.