Old Calendar and New Calendar: Why Orthodox Feasts Have Two Dates

Orthodox feasts have two dates because the Orthodox Churches keep two church calendars. Old Calendar Orthodox churches (Russia, Serbia, Jerusalem, Georgia, Mount Athos) follow the Julian Calendar, which today runs 13 days behind the civil calendar. New Calendar churches (Constantinople, Greece, Antioch, Romania, Bulgaria and others) keep fixed feasts on the civil date. So it is the same feast on the same church date: Christmas is 25 December for everyone, but on the Old Calendar that day falls on 7 January. And Pascha, the feast of feasts, is kept on one Sunday by almost all of them.

Where the two calendars came from

For the first fifteen centuries, the whole Church used the Julian Calendar, set up under Julius Caesar. Its year averages 365.25 days. The sun’s year is a little shorter, so the calendar slowly slipped behind the seasons.

In 1582 Pope Gregory XIII introduced a corrected calendar. It moved the start of spring back to 21 March and changed the leap-year rule: a century year is a leap year only if it divides by 400. So 1700, 1800 and 1900 had no 29 February, and 2100 won’t either. That Gregorian Calendar is the civil calendar on your phone today.

The Orthodox did not take it up for church use. As Fr Lawrence Farley of the OCA notes, countries like Russia adopted the new calendar for civil life but kept the Julian one for their church feasts.

What the “New Calendar” is

In 1923 a meeting called by the Ecumenical Patriarchate in Constantinople approved a third option: the Revised Julian Calendar, often called the New Calendar. It was not the Gregorian Calendar, though it lines up with it day for day until the year 2800.

The meeting also proposed a new way to find the date of Pascha. That part was never put into practice, so the reform stopped halfway: new dates for fixed feasts, the old Paschalion for Easter.

Which churches use which calendar

New Calendar (fixed feasts on the civil date):

• The Ecumenical Patriarchate of Constantinople, and with it the Greek Orthodox Archdiocese of America
• The Patriarchates of Alexandria and Antioch (including the Antiochian Archdiocese)
• The Churches of Greece, Cyprus, Romania, Bulgaria and Albania
• The Orthodox Church in America, which introduced the revised calendar in the 20th century (some OCA parishes still keep the Old Calendar)
• The Orthodox Church of Ukraine, which moved to the New Calendar from 1 September 2023 and let parishes and monasteries that wished to stay on the Old Calendar do so

Old Calendar (everything on the Julian Calendar):

• The Patriarchate of Jerusalem
• The Russian Orthodox Church, including the Russian Orthodox Church Outside of Russia (ROCOR)
• The Serbian and Georgian Churches
• The monasteries of Mount Athos

If you are not sure what your own parish follows, look at its Christmas service. Liturgy on the morning of 7 January means the Old Calendar.

Pascha: one date for nearly everyone

The movable feasts are a different matter. Almost every Orthodox Church, Old or New Calendar, finds the date of Pascha on the Julian Calendar with the ancient Alexandrian Paschalion. The Church of Finland is the one exception: it keeps Pascha on the Western date.

That means Great Lent, Holy Week, Pascha, Ascension and Pentecost fall on the same days in a Russian parish and a Greek one. In 2027, Pascha is on 2 May. If you are planning gifts, see our Pascha gift guide.

Christmas: 25 December and 7 January

This is the date people ask about most. Old Calendar Orthodox Christmas is not a different feast from Western Christmas. It is 25 December on the Julian Calendar, which is 7 January on the civil calendar. Fr Farley puts it plainly: Orthodox on the Julian Calendar also celebrate Christmas on 25 December; they just reach that date on 7 January.

So in many American families you may keep Christmas twice: once with the neighbors and in-laws, and once with grandmother’s parish. Our Christmas gift guide covers both.

Worked examples: fixed feasts on both calendars

Add 13 days to get the Old Calendar civil date (until 2100):

How to read an Old Calendar wall calendar

A Russian or Serbian church calendar usually prints two numbers for each day. One is the civil date; the other, often smaller or in brackets, is the Julian church date. When you see “19 December (6 December)”, read it as: today the Church keeps St Nicholas, whose feast is 6 December on the church calendar, and on your kitchen calendar that is 19 December.

English-language Old Calendar calendars sometimes mark this as “N.S.” (new style, civil) and “O.S.” (old style, Julian). The saint listed belongs to the old-style date.

The gap is growing

The 13-day gap holds from 1900 to 2100. The Julian Calendar has a leap day on 29 February 2100; the civil calendar does not. From mid-March 2100 the gap becomes 14 days, and Old Calendar Christmas will fall on 8 January from then on.

What it means for name days and gifts

Your name day follows your parish calendar. A Nicholas in a Greek or Antiochian parish keeps his name day on 6 December; a Nikolai in a Russian or ROCOR parish keeps it on 19 December. St Nicholas’s spring feast, the translation of his relics to Bari, is 9 May (22 May on the Old Calendar). Our name days guide explains how families keep the day, and the patron saint finder helps you find a patron saint by first name. You can also read the life of St Nicholas.

For a St Nicholas Day gift, the St Nicholas Gift ($99) pairs the St Nicholas and Guardian Angel diptych with an IC XC NIKA medallion, in a gift box.

Christmas order-by dates

To arrive by 25 December, order by 15 December without Consecration, or by 10 December for a cross, icon or medallion with Consecration ($49). For Christmas on 7 January, order a cross, icon or medallion with Consecration by 24 December. Our priest consecrates each item with holy water and the prayers of the Church; orders with Consecration of a cross, icon or medallion ship in 3–8 business days, and consecrated items are final sale. Consecrated folding diptychs, where a diptych’s page offers Consecration, ship in the normal time. We offer free shipping on orders of $99 or more.

Two dates on the calendar, one feast in the Church. Whichever day your family keeps, you are celebrating together with the whole Orthodox world.