For the vast majority of the world, including here in the UK, Christmas Day is December 25th.
It is the day that has become almost universally recognized to mark the birth of Jesus Christ, celebrated by eating too much stuffing and falling asleep on the sofa with a glass of port in hand (other methods of celebration are available).
But a good chunk of Christians around the world don’t actually celebrate the 25th and instead wait for the New Year.
Orthodox Christians follow a different calendar from the Gregorian calendar generally used in Western countries.
This means that the Russians, in particular, still have some time to wait for their festivities.
When is Orthodox Christmas?
Orthodox Christians celebrate Christmas on January 7.
However, the celebrations officially begin at midnight on Christmas Eve.
Why is the date different?
The reason these dates are different is due to the calendars used to calculate the dates.
Julius Caesar introduced a calendar in 46 BC on the advice of the Egyptian astronomer Sosigene, who had calculated the lunar year. But his measurements were about 11 minutes in error, and over the centuries the dates of major Christian holidays had drifted so much that it became a problem.
To solve this problem, the Gregorian calendar was introduced by Pope Gregory in 1582, and it is the one we still use today.
Spain, Portugal, France, Poland, Italy, the Catholic Netherlands and Luxembourg were the first nations to adopt it.
But, in much of the Soviet bloc and the Middle East, the Julian calendar is still in use.
This means there is a 13 day gap between the two calendars, so Christmas Day in these countries falls on what we now call January 7th.
In May 1923, a group of Orthodox leaders gathered to address the issue as the holidays continued to drift.
States like Greece, Cyprus and Romania have agreed to switch to the new calendar, but other Orthodox churches, like those in Russia and Egypt, have refused.
Which countries celebrate Christmas on January 7th?
Many countries celebrate Christmas on this day, including Russia, which is home to more than a third (39%) of the world’s Christians.
Some Orthodox countries – like Greece, Cyprus and Romania – now use December 25 to change the calendar. However, they still have Epiphany celebrations, which is January 6 and Christmas Eve according to their old Julian calendar.
Those who still celebrate in January include:
The Armenian Apostolic Church celebrates January 6 because the country was not influenced by the Roman Empire or the Julian or Gregorian calendars.