Orthodox Pascha and Western Easter follow the same ancient rule but use different calendars to calculate it. That’s the short answer.
The longer story goes back to the Council of Nicaea in 325 AD. The bishops gathered there established that Pascha should fall on the first Sunday after the first full moon following the spring equinox. This was meant to unite the whole Church in celebrating the Resurrection on the same day. And for over a thousand years, it worked.
But in 1582, Pope Gregory XIII reformed the Western calendar. The old Julian calendar (named for Julius Caesar) had been drifting out of sync with the seasons by about three days every four centuries. By the 16th century, the calendar was off by ten days. Gregory’s reform skipped those days and tweaked the leap year rules to prevent future drift. Most of the Western world eventually adopted this Gregorian calendar, and it’s what your phone and the refineries in Beaumont use today.
The Orthodox Church kept the Julian calendar for liturgical purposes. We didn’t reject it out of stubbornness. The calendar change came from papal authority alone, without an ecumenical council, and the Orthodox Church makes major liturgical decisions through consensus of all the bishops. We’re still waiting for that conversation to happen properly.
Here’s where it gets technical. When we say Pascha falls on the first Sunday after the first full moon after the spring equinox, we have to ask: which calendar’s spring equinox? The Orthodox use March 21 on the Julian calendar, which currently falls 13 days later than March 21 on the Gregorian calendar (that gap grows by three days every four centuries). So our starting point is already nearly two weeks later than the Western one.
There’s another layer. The Orthodox Church maintains that Pascha shouldn’t come before the Jewish Passover. This isn’t arbitrary. Christ was crucified during Passover week. The Gospels are clear about the timing. Our Pascha celebrates the fulfillment of that original Passover, so it makes theological sense that it should follow rather than precede it. The Western churches dropped this requirement when they adopted the Gregorian calendar, which means their Easter can sometimes fall before Passover. For us, that feels backwards.
Some years the calculations align and we celebrate together. 2025 is one of those years. But most years we don’t. When your Baptist coworkers are hunting eggs in early April, we’re often still in the middle of Great Lent, fasting and preparing. Our Pascha might come a week later, or five weeks later, depending on how the lunar cycles and calendar math work out.
People sometimes ask if we’ll ever change. Maybe. There have been discussions at various inter-Orthodox gatherings about adopting a common date, either by switching to the Gregorian calendar or by using astronomical calculations that both East and West could agree on. But any change would require agreement among all the Orthodox Churches, and that hasn’t happened yet. We don’t move quickly on these things. We’ve been celebrating the Resurrection for two thousand years. We can wait until we’re all on the same page.
Metropolitan Kallistos Ware once noted that the different dates, while inconvenient, do have an unintended benefit. They extend the season of Paschal joy across the Christian world. When the West celebrates, we’re praying for them. When we celebrate, they’re praying for us. The whole springtime becomes a longer witness to the Resurrection.
If you’re new to Orthodoxy and your family celebrates Easter on the Western date, this can feel awkward at first. You might be fasting while they’re feasting. But most families figure it out. You can join them for their meal and still keep your fast. Or you can explain that you’ll celebrate with them again in a few weeks when your Pascha comes. Most folks in Southeast Texas understand keeping to your church’s calendar, even if they think it’s a little peculiar.
The date difference isn’t about being difficult. It’s about faithfulness to the ancient rule as the Orthodox Church has always understood and practiced it. We’re keeping the same Paschal calculation that our fathers and mothers in the faith used, tied to the same liturgical calendar they used. When you celebrate Pascha with us, you’re celebrating on the same day that Orthodox Christians have celebrated for centuries, using the same reckoning that goes back to Nicaea. There’s something solid in that continuity, even if it means your Easter basket comes later than your neighbor’s.
