Why do most Orthodox people celebrate Christmas on January 7?

A small revolution in Christianity. For the first time in modern history, Christmas was celebrated in Ukraine at the same time as in the Western world, on December 25. This event is the result of a decision by the Orthodox Church of Ukraine and the symbol of rapprochement with Europe, which at the same time underlines the distance that kyiv is taking vis-à-vis Moscow.

This upheaval of dates recalls the difference which divides the different Christian Churches concerning the date of the celebration of Christmas. The overwhelming majority of Orthodox people (notably the Russian Orthodox Church) but also some Greek Catholics will celebrate Christmas on the night of January 6 to 7 this year, 13 days after December 25. How can we explain such a discrepancy?

It's all a question of calendar differences. The vast majority of Orthodox people in fact retain the so-called “Julian” calendar, introduced by Julius Caesar in 46 BC. The consul had introduced this calendar in which a year corresponds to 365 days, plus 1/4 of a day. This duration, however, exceeds the astronomical year by 11 minutes and 14 seconds: the gap between the solar year and the calendar year widens over the years. In fact, the Julian calendar is extended by one day every 128 years compared to the solar year.

In the 16th century, the gap between the Julian calendar and astronomical observations reached 10 days. In 1570, Pope Gregory XIII appointed a commission of astronomers to reform the calendar and resolve this problem of accumulated delays. On February 24, 1582, a papal act established a new calendar and introduced leap years every four years. The 10 extra days are removed to align with astronomical observations. In France, we therefore go from Sunday 9 to Monday 20 December 1582: the modern calendar is born.

The reform was gradually adopted by Catholic states. For their part, a large majority of Orthodox Churches (those of Russia, Serbia, Georgia and Ukraine until now), which separated from the Roman Catholic Christian region following the 1054 schism between the Christians of the East and West continue to follow the Julian calendar. The gap therefore continues to grow between the latter and the Gregorian calendar: it is currently 13 days, and will increase to 14 days in 2100.

In the context of the war in Ukraine, the Ukrainian Orthodox have nevertheless decided to change their tune. The Ukrainian Orthodox Church has in fact chosen to authorize its faithful to celebrate the birth of Jesus Christ on December 25, to distance themselves from Russian traditions and escape the influence of the Moscow Church. In July, Volodymyr Zelensky therefore formalized the move of Christmas celebrations from January 7 to December 25. The text voted on by Ukrainian MPs then explained that Ukrainians wanted to “live their own lives, with their own traditions, their own holidays”. A way, the text further noted, to “abandon the Russian heritage which imposed Christmas celebrations on January 7.”