Jump to Why the date moves Two calendars, two calculations But my Orthodox parish celebrates Christmas on December 25 Is the Jewish date of Passover the deciding rule? The date serves the feast
Some years, Orthodox Pascha and Western Easter fall on the same Sunday. In other years they are separated by one week—or several.
The difference is not caused by Orthodox Christians believing that the Resurrection occurred on a different day of the week. All celebrate the empty tomb on Sunday.
The disagreement concerns how the annual date is calculated.
Why the date moves
Christmas is attached to a fixed calendar date. Pascha is a movable feast whose date is related to both the spring equinox and the lunar cycle.
This reflects the Gospel setting of Christ’s death and Resurrection at the time of Passover. The Church’s annual celebration developed within that biblical and Jewish paschal setting.
The First Ecumenical Council, held at Nicaea in AD 325, established a common celebration of Pascha for the Church rather than leaving local communities to follow conflicting calculations. The surviving evidence does not give us a neat modern formula issued as a Nicene canon, so confident slogans about one simple “rule of Nicaea” should be used cautiously.
What emerged was the paschalion: a system for determining the Sunday of Pascha from an ecclesiastical equinox and full moon.
Two calendars, two calculations
The Julian calendar used in the ancient world gradually drifted from the astronomical year. In 1582, under Pope Gregory XIII, the Western Church introduced the Gregorian calendar to correct that drift and revised the tables used for Easter.
The Orthodox world did not generally adopt the Gregorian paschal calculation. Most Orthodox churches continue determining Pascha according to the traditional Julian-based paschalion, although limited local exceptions exist.
Because the two systems may assign different dates to the ecclesiastical equinox and full moon, they sometimes identify different Sundays.
But my Orthodox parish celebrates Christmas on December 25
This is where the calendar question becomes confusing.
Some Orthodox churches use the Revised Julian or civil Gregorian calendar for fixed feasts such as Christmas while continuing to use the traditional Orthodox paschalion for Pascha and the movable feasts connected with it. Other Orthodox churches retain the Julian calendar for fixed feasts as well.
Two Orthodox parishes may therefore celebrate Christmas on different civil dates while still celebrating Pascha together.
This is why “old calendar” and “new calendar” do not by themselves explain every date on an Orthodox calendar.
Is the Jewish date of Passover the deciding rule?
A common explanation says Orthodox Pascha must always occur after Jewish Passover. The historical relationship is more complicated.
Christian Pascha is unquestionably rooted in the biblical Passover. But the Church does not wait each year for the date announced by the modern Jewish calendar and then choose the following Sunday. The traditional Christian paschalion and the modern Jewish calendar use their own methods of calculation.
Reducing the entire issue to “Orthodox Easter must come after Passover” leaves out the calendar and astronomical questions that actually produce the dates.
The date serves the feast
Calendar calculations matter because common worship matters. The divisions that prevent all Christians from celebrating together should grieve us.
But the calendar is not the Gospel.
Pascha proclaims that Christ has trampled down death by death. The fasting season, Holy Week, midnight procession, proclamation of the Resurrection, Eucharist, and fifty-day celebration all exist to bring the Church into that victory.
Knowing why the dates differ can end confusion. It should not become another opportunity for pride.
Whenever Pascha falls, the announcement is the same:
Christ is risen.
A note. These articles explain what the Orthodox Church teaches and why. They are not spiritual direction. Anything touching your own rule of prayer, fasting or confession belongs with your priest or spiritual father, who knows you and your circumstances.
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