Different Dates for Easter?
This year, all Christians across the world will celebrate Easter on the same day. This is unusual. Typically, Catholic Christians and Eastern Orthodox Christians observe Easter separately, using two different calendars. The last time our Easters matched was in 2017; the next time will be 2028.
What’s going on here? What explains this discrepancy?
The dating of Easter is tied to the Jewish feast of the Passover. The final events of Jesus’s life all took place within the context of the Passover. The Last Supper was a Passover meal. More than that, Jesus’s death and resurrection is understood as the definitive Passover sacrifice. Indeed, we say that, in his resurrection, Jesus passed over from death into life. And so Christianity’s Easter is irrevocably tied to the date of Judaism’s Passover.
The Jewish people, of course, date the Passover upon instructions from the Book of Leviticus: “In the first month, on the fourteenth day of the month in the evening, is the Lord’s Passover” (Lev 23:5). The Jewish lunar calendar names this first month “Nisan.”
And yet, from pretty much the beginning, Christians were unable to get on the same page with respect to the proper date for Easter.
There are three stages to the history of this controversy.
First Stage
In the 2nd Century, Christians in Rome, wanting to recognize the fact that Jesus rose on a Sunday, celebrated Easter on the Sunday following the 14th of Nisan. On the other hand, in Asia Minor (present-day Turkey), as well as in Jerusalem and Syria, Christians celebrated Easter on exactly the 14th day of Nisan, no matter what day of the week it was. These Christians were sometimes called “Quartodecimans” (quarta decima means “fourteenth” in Latin).
It’s unclear which tradition is the more ancient. The Christians in Rome claimed they received the practice of celebrating Easter on a Sunday from the Apostles Peter and Paul, who died in Rome. The Quartodecimans claimed their tradition came from the Apostle John. Saint Polycarp, who was a disciple of the Apostle John, claimed he learned the practice from John himself.1
Long after St. Polycarp, though, the Quartodecimans were excommunicated by the Pope and formed their own separated church, only dying out after several centuries.
Second Stage
After a hundred years or so, the controversy emerged again. This time, the question was not whether or not Easter should be celebrated on a Sunday. The question was: which Sunday?
The Christians of Antioch (where the Quartodecimans formerly flourished) simply borrowed the Jewish calendar to determine the date of Easter. Easter was just the Sunday after the Jewish people celebrated their Passover. Most other Christians, though, ignored the Jewish calendar and calculated the date for Easter on their own using the Julian Calendar of the Romans. Because they were using two separate astronomical calendars, though, there were many years in which Christians in Syria celebrated Easter on a different date from Christians in the rest of the world.
In 325, the Council of Nicaea took up this discrepancy and determined that Christians would universally utilize the Julian Calendar of the Romans, not the calendar of Judaism. Regardless of the Jewish Passover, then, Christians were to celebrate Easter on the Sunday after the first full moon following the vernal equinox (the vernal equinox is when the sun is exactly above the equator).
Third Stage
For several hundreds years, this worked. Sort of.
It turns out that the Julian Calendar the Church had been utilizing was actually inaccurate. In the 16th century, after several hundred years, the real vernal equinox was actually 10 days off from the calendar’s date.
In response, Pope Gregory XIII commissioned a new calendar – the Gregorian Calendar – which rectified the 10 day discrepancy. After October 4th, 1582, the people of the Western world woke up, not to October 5th, but to October 15th.
Herein lies the next difficulty – indeed, the difficulty we’re still dealing with.
Five hundred years before Gregory changed the calendar, the Eastern and Western churches split in two. This is the Great Western Schism of 1054, which saw the Catholic Church and Eastern Orthodoxy divide from each other. The difficulty was that, when Gregory promulgated his new calendar, none of the churches of Eastern Orthodoxy went along with him. Indeed, to this day, Eastern Orthodoxy calculates the date of Easter using the Julian Calendar while the Catholic Church uses the new Gregorian calendar.
See Eusebius, Church History, Book V, Chapter 24.