Some Orthodox churches celebrate Christmas on December 25th. Others celebrate it on January 7th. It’s the same feast, but they’re using different calendars.
Here’s what happened. In 1923, a congress of Orthodox churches met and proposed adopting what’s called the Revised Julian Calendar for fixed feasts like Christmas and Epiphany. The old Julian Calendar, which the Church had used since ancient times, had drifted 13 days behind the solar year. This new calendar would correct that drift and align Orthodox feast days with the civil calendar most of the world was using.
Some churches adopted it. Greece did. Constantinople did. The Antiochian Church eventually did (though we initially resisted). Others refused. Russia kept the old calendar. So did Serbia and Jerusalem. Mount Athos still uses it today.
This wasn’t a theological argument about what we believe. Nobody was changing doctrine. But it became controversial anyway, and for reasons that made sense to people at the time. There’d been no ecumenical council to authorize the change. Some saw it as caving to Western influence or as a step toward compromising with Rome. In Russia, the chaos of the Revolution made any change feel dangerous. Traditionalists worried it would lead to other innovations.
So now we’ve got what looks like a mess. You can visit an Antiochian parish in Beaumont and celebrate the Nativity on December 25th, then drive to a Russian parish in Houston and find they won’t celebrate it until January 7th (which is still December 25th on the Julian Calendar, it’s just 13 days behind).
But here’s the thing. We’re still in communion with each other. An Antiochian Christian can receive the Eucharist at a Russian parish and vice versa. The calendar difference doesn’t create a sacramental barrier. We’re one Church using two different administrative systems.
And there’s something else that keeps us unified. Every Orthodox church, whether it uses the old calendar or the new one, calculates Pascha the same way. We all use the ancient Paschal tables based on the Julian Calendar. That means Orthodox Easter falls on the same day for everyone, whether you’re in an Antiochian parish or a Serbian one or a Greek one. (It often differs from Western Easter by a week or more, sometimes up to five weeks, but that’s a different issue.)
The fixed feasts are what differ. Christmas. Epiphany. The feast of St. Nicholas. If your parish uses the Revised Julian Calendar, you celebrate these on the same dates as the Western calendar. If your parish uses the Old Calendar, you celebrate them 13 days later. But the movable feasts, everything connected to Pascha, which means Lent and Pentecost and all the Sundays of the year, those line up for everyone.
It can feel confusing when you’re new to Orthodoxy. You might wonder if this means we’re divided or if one group is more authentically Orthodox than the other. We’re not divided in any way that matters for salvation. The Church isn’t broken over this. There are some groups called Old Calendarists who’ve broken communion over the calendar issue, treating it as a test of Orthodoxy, but they’re outside the mainstream of the Church. For the rest of us, it’s a practical difference we live with.
If you’re visiting St. Michael and you’ve got family at a Russian or Serbian parish, you’ll celebrate Christmas on different days. That’s awkward for family gatherings, sure. But you’re celebrating the same feast, venerating the same Christ, receiving the same Mysteries. The calendar we use doesn’t change what we believe about the Incarnation or the Resurrection or anything else that matters for our salvation.
Most Orthodox Christians worldwide use the Old Calendar, Russia’s huge, and so are the other churches that kept it. But in America, you’ll find both. The Antiochian Archdiocese uses the Revised Julian. So does the Greek Archdiocese. The OCA and ROCOR use the Old Calendar. When you’re visiting a new parish, it’s worth checking which one they follow so you don’t miss a feast day.
The calendar question isn’t going away anytime soon. It’s been a century and we still haven’t resolved it. But it also hasn’t torn the Church apart, which tells you something about how we understand unity. We’re not united by administrative uniformity. We’re united by the same faith, the same sacraments, the same bishops in apostolic succession. The rest is details we can disagree about and still be one Church.
