Calendars are hugely important for our lives – much more important than we often give them credit for! This is especially true for Christians. Calendars help us to celebrate feasts and fasts, and to remember events in our own spiritual life, like our baptism. Yearly feasts and commemorations make the events of our salvation present to us in a way that is both predictable and new: every day of the liturgical year has something new to tell us, while still reminding us of the essential facts of our faith. As the Apostle Paul says, “Jesus Christ is the same yesterday and today and forever.” (Hebrews 13:8)

This past December, liturgical calendars suddenly got a lot of attention in the media. This followed the decisions of the Ukrainian Catholic Church and the Orthodox Church of Ukraine, two of the largest churches in Ukraine, to stop using the Julian Calendar, often called the “Old Calendar,” and start using what is commonly called the “Revised Julian” calendar. Many Old-Calendar parishes outside Ukraine, both Catholic and Orthodox, decided to follow suit. The media eventually noticed the change around Christmas: after more than a century of Ukrainian-Canadians celebrating “Ukrainian Christmas,” suddenly these communities were celebrating on December 25, just like everyone else.

However, dig a bit deeper, and many people are perplexed to learn that the calendar change only affects certain feasts, like Christmas and Theophany. The date of Easter (called Pascha by Orthodox and Eastern Catholics) isn’t being changed (at least in Ukraine); nor are the other commemorations and fasts that lead up to and follow after it. The reason for this is somewhat complicated, but I’ll try to explain it here.

First, a short history lesson: in 1582, Pope Gregory XIII updated the Julian calendar, since it had fallen 10 days behind where it should have been. In other words, the Julian calendar was inaccurate. The new dating system, called the “Gregorian calendar,” was accepted in Catholic countries, and gradually Protestant countries adopted it as well. However, Orthodox Christians and Eastern Catholics, including on the territory of modern Ukraine, continued to use the “Old” or Julian Calendar in their religious life for the next several centuries. Over time, some Orthodox and Eastern Catholics (including immigrants to Canada) learned to use the “New” Calendar in their civil life, but they simply kept two dates in their minds: “My prayer book says that Christmas is December 25th, but I know that I’ll need to ask my boss for January 7th off from work.”

Orthodox Christians gradually started adopting the New Calendar in the 1920s. However, only some Orthodox Churches made this change: some Churches simply weren’t interested, while others were restrained by political circumstances and persecution. This included millions of Orthodox in Ukraine and Russia, then part of the Soviet Union. So, the Orthodox Churches that did make the switch decided to do something creative, though a bit confusing: they moved the dates of fixed feasts, without changing the celebration of moveable feasts. (FYI: Fixed feasts fall on the same day each year, like Christmas on December 25, or St. Michael the Archangel on November 8. Moveable feasts, on the other hand, change dates from one year to the next: think of feasts like Easter, Palm Sunday, or Pentecost, which are always on a Sunday, but not on the same calendar date). The Orthodox Churches took this half-step for the sake of unity: they didn’t want to celebrate Pascha (Easter) on a different date than their fellow Orthodox in other countries, who either couldn’t, or wouldn’t, make the change.

The result was a hybrid calendar, generally called the “Revised Julian” calendar. Today, this calendar is used by more than two-thirds of the different Orthodox Churches. It gives all fixed feasts according to the Gregorian calendar, but Pascha and other moveable feasts have stayed on the Julian date. So, if I want to go to Divine Liturgy on my ‘name’s day’ (and let’s say my name is Sophia), I just remind myself when St. Sophia’s feast day is (it’s September 17, and that never changes). There’s no adding or subtracting dates, and no need to look at a special Church calendar: the iPhone or Hallmark calendar will do just fine. But, for Easter/Pascha, and all the feasts and other dates that are dependent on it, an Orthodox Christian did need a special church calendar (or she had to google “when is Orthodox Easter this year”), because those dates didn’t follow the Gregorian calendar.

This back story is a bit complicated, but it’s important for understanding why things in the Ukrainian churches have happened the way they did. In 2018, the Orthodox Church of Ukraine had been granted autocephaly (effectively independence) by the Patriarch of Constantinople, over the strong objections of the Russian Orthodox Church. It’s not hard to imagine that some people in the Orthodox Church of Ukraine were already thinking about moving to the “Revised Julian” calendar, since this would show their solidarity with other Orthodox Christians, like those in Constantinople, Greece, and Alexandria, that had accepted them into communion. There was also openness to a calendar switch in the Ukrainian Catholic Church. Patriarch Sviatoslav had said publicly that such a switch was possible: the main caveat was that the Ukrainian Catholic Church didn’t want to start celebrating feasts on a different date than its Orthodox counterparts in Ukraine. Until they switched, the UGCC was probably going to stay on the Old Calendar, at least in Ukraine. In both cases, a change to the calendar (or a decision not to change it) was being considered for the sake of unity: in the case of the Orthodox Church of Ukraine, unity with their fellow Orthodox elsewhere in the world, and in the case of the Ukrainian Catholic Church, hoped-for unity with their Orthodox neighbours.

This brings us to February 2022, and the full-scale Russian invasion of Ukraine. In 2023, the UGCC, followed soon after by the Orthodox Church of Ukraine, both announced that they would switch to the revised Julian calendar. Sadly, this decision is, to some extent, a sign of disunity: many Christians in Ukraine want to send a signal about who they are, and are not, in union with.

To be clear, the decision of the Ukrainian Catholic Church only effected the territory of Ukraine itself: Ukrainian Catholics outside Ukraine are free to remain on the Old Calendar. A small number of rural parishes have, so far, remained on the Old Calendar, but most Ukrainian Catholic churches in North America seem to have made the shift pretty quickly. In most cases, this is justified by an appeal to unity, in this case, unity between Ukrainian Catholics in Ukraine and those living elsewhere in the world.  

Similarly, the decision of the Orthodox Church of Ukraine has not authority outside of Ukraine, but Ukrainian Orthodox living outside of Ukraine largely followed suit. And, while the Ukrainian Catholic Church moved first, it seems likely that its decision to adopt the Revised Julian calendar was motivated, once again, by a desire for unity between Catholics and Orthodox in Ukraine.

Calendars are important for Christian life, not least because they help create unity through the cycles of feasts and fasts that they establish. Unfortunately, Christians use different calendars, and this often serves to exacerbate our divisions. Celebrating on one date and with one group of Christians often means not celebrating with another group. Christians in Ukraine, and many Ukrainian Christians in Canada, are now using a different calendar. This change signals unity with some Christians, a hoped-for unity with other Christians, and, by implication, the disappointing lack of unity between Ukrainian Christians and the largest Church that still uses the Old Calendar, the Russian Orthodox Church.

The key word in this summary is unity, a word that we find echoed in John 17, where Jesus prays for the unity of all those who call themselves by his name. Let’s pray for that unity, even if it seems a remote possibility.