Why Do Eastern Orthodox and Western Churches Celebrate Christmas on Different Dates?

Question

For most of the Western world, Christmas is celebrated on December 25. However, Orthodox Christians usually celebrate Christmas on January 7 instead. How did this come to be? Is there a theological difference underlying this difference or is it simply a matter of the Gregorian calendar vs. the Julian calendar?

Answer 1

Why Do Eastern Orthodox and Western Churches Celebrate Christmas on Different Dates?

This is simply due to the fact that some Orthodox Churches still follow the Julian Calendar for liturgical purposes. The churches of Constantinople, Cyprus, Greece, Romania, Russia, and Serbia all follow the Julian Calendar and are out by 11 days according to the Gregorian Calendar.

The Orthodox Calendar a celebrates Christmas on December 25th (Old Style) or January 7th (New Style).

At the conference, Serbian scientist Milutin Milanković proposed a solution: a new version of the Julian calendar that shares its dates with the Gregorian calendar, though it doesn’t share every leap year. Known as the revised Julian calendar, it was adopted by several Orthodox churches, including the churches of Greece, Cyprus, and Romania. Those churches now celebrate Christmas on December 25.

But other Orthodox churches, like those of Russia and Egypt, refused. And still others, like Poland, adopted Milanković’s calendar, then dropped it later. They celebrate Christmas on January 7—until 2100, that is, when it will move to January 8 as the calendar continues to drift. - Why some people celebrate Christmas in January