This article was first published in the June 2025 issue of Transforming Worship News (formerly Praxis News of Worship).
The date of Easter is often regarded as rather complicated, too complicated for nearly everyone to worry about. But it links us with the origin of the annual festival, and the way the early Church celebrated the resurrection.
When the Emperor Constantine decided that Christianity was the best hope of unifying his empire, he found disagreement on several topics, including the nature of Christ and the date on which to hold an annual celebration of his resurrection. The Council of Nicaea in 325 attempted to resolve both issues, agreeing a statement of belief and formalizing the date of Easter.
The story begins with the Jewish festival of Passover, held at the first full moon of the spring, when the moon lights the sky all night. In the Jewish lunar calendar this day is 15 Nisan, and the previous day, 14 Nisan, is the day of preparation. In the late afternoon of that day, until the Temple was destroyed, Passover lambs were slaughtered in the Temple precincts. They were then roasted and eaten at the Passover meal that began with the full moon at sunset, the start of 15 Nisan. In the fourth gospel, the crucifixion was on 14 Nisan, and in the synoptics on 15 Nisan.
There is no explicit evidence in the New Testament of a yearly Easter. The focus in the early Church was the weekly celebration of the resurrection on the first day of the week, every Sunday. Although it is not entirely clear – and there may have been a cover up – it seems that Christians in Jerusalem and the Jewish diaspora did keep an annual festival, but Gentile Christians probably didn’t. The former group kept an annual celebration of both the crucifixion and resurrection on 14 Nisan, whichever day of the week that fell on.
Perhaps influenced by this annual feast kept in the diaspora, other Christians began to observe it and a fast on the previous day. But rather than keeping it on 14 Nisan they celebrated the following Sunday, the day of the weekly commemoration of the resurrection. Perhaps just as today, it was more convenient to transfer weekday festivals to Sunday.
These two groups co-existed until at the end of the second century, Pope Victor I controversially excommunicated those who kept 14 Nisan – the Quartodecimans (or “fourteeners”). A century later the dispute had not ended although the Quartodecimans were a distinct minority. So when, commanded by Constantine to agree a common date, the bishops assembled at Nicaea it was not surprising that majority opinion, favoured by Rome and other major sees, prevailed. The Council ruled that the annual paschal feast, celebrating the resurrection, should be observed on the Sunday after the first full moon of the spring, the full moon after the equinox.
The Council did not prescribe how this might be determined in advance, and initially it was perhaps left to direct observation. Competing tables of dates soon emerged, frequently based on a 19-year lunar cycle that had been known since at least the Babylonians. The date of the equinox, which in the first century had fallen on 25 March, had by the fourth century drifted to 21 March. Tables from Alexandria were generally regarded as the best, and the declaration each year from that see of the date of Easter was usually followed, though for many years the see of Rome used different tables so occasionally Easter would fall on another date. Eventually the tables compiled and extended by the sixth-century monk Dionysius Exiguus were accepted as definitive. These continued in use throughout the Church, across the schism between East and West. As the middle ages wore on it was recognised that both lunar and solar components of the tables were increasingly inaccurate, but it was not until after the Reformation that Pope Gregory XIII unilaterally introduced a modified calendar with self-correcting lunar tables. Although these were gradually accepted by the churches of the Reformation they have not been adopted in the East, at least not for determining Easter.
In the twentieth century there were some moves to fix the date of Easter, but at the end of the century the World Council of Churches proposed abolishing calculated tables based on the approximate 19-year cycle and instead using accurate astronomical calculations of the equinox and the full moon as observed in the time zone of Jerusalem. They suggested this might be adopted in 2000 when both Eastern and Western calculations coincided on the same date. There was some support for this from Rome, from Anglicans and various churches of the Reformation and some Orthodox churches, but it was far from universal. In this 1700th anniversary year of Nicaea, when Easter dates again coincide, the WCC has re-iterated its proposal. Once again, it seems unlikely to gain enough support to be brought in.
Simon Kershaw remembers trying to calculate Easter from the tables in the BCP while enduring long sermons as a young chorister at Evensong. He has continued to calculate and write about the date of Easter.
Isn’t it possible that the first opponents of the Quartodecimans, who based themselves on John’s Gospel, were really ‘Quintodecimans’, who based themselves on the Synoptic chronology and thought that Jesus had died on the 15th?
Eusebius led the way for us to regard the argument as date versus day, when its real basis was date versus date. To this day there is hardly any consciousness of this important New Testament crux
Thanks for your comments. As I mentioned elsewhere, the article is a bit of a canter across the field, limited primarily by the word count allowed in a print publication. Although I did mention the chronological difference between the Synoptics and the Fourth Gospel, I did rather gloss over it.
I should perhaps add a short bibliography – primarily Talley’s Origins of the Liturgical Year and Bradshaw’s Passover and Easter: Origin and History to Modern Times and Origins of Feasts, Fasts and Seasons in Early Christianity. Also Mosshammer’s Easter Computus and the Origins of the Christian Era.