Millions of Christians, including those in Eastern Europe and across the Arab world, such as Palestine, and Egypt, are celebrating Christmas today.
Christmas Day commemorates the birth of Jesus Christ, who was born in Bethlehem.
However, for these communities, which number about 250 million people, the most important day of the season is not December 25, but January 7. In this visual explainer, Al Jazeera illustrates what cultural and historical reasons led to this difference in Christmas celebrations.
Why are there two Christmases?
The reason some Christians celebrate Christmas on January 7 is not because they believe Jesus was born on a different day, but because they are using a different calendar.
The difference in the timing of Christmas stretches back to 1582, when Pope Gregory XIII ruled that the Catholic Church should follow a new calendar, called the Gregorian calendar, to replace the less accurate Julian calendar.
The Julian calendar, which was introduced by Julius Caesar in 46 BC, overestimated the solar year by 11 minutes, causing the seasons to eventually drift out of place.
Where the Julian calendar loses one day every 128 years, the Gregorian calendar loses one day every 3,236 years, making it a much more accurate approximation of a true solar year.
To get back on track, the world had to essentially skip 10 days to make up for the missing time that had accumulated over the 15 centuries.
While most of the world adopted the new Gregorian calendar, many Orthodox and Eastern Christian churches have stayed with the Julian calendar to maintain their traditions.
Fast forward to today, and the Julian calendar is currently 13 days behind the Gregorian calendar. This means that December 25 on the Julian calendar actually falls on January 7 on our modern calendars.
Interestingly, if the Orthodox Church continues to use the Julian calendar, the date of Orthodox Christmas will shift to January 8 in the year 2101, as the 13-day gap increases to 14 days.
Who celebrates Christmas on January 7?
Of the estimated 2.3 billion Christians worldwide, about 2 billion celebrate Christmas on December 25. This includes about 1.3 billion Catholics, 900 million Protestants, and some Orthodox Christians who have adopted the Gregorian calendar.
The remaining 250-300 million Christians, primarily Orthodox and Coptic denominations, celebrate Christmas on January 7, which is also known as Old Christmas Day.
Notable groups that celebrate Christmas on January 7 include:
The Russian Orthodox Church: The largest group following this tradition.
The Serbian and Georgian Orthodox Churches.
The Coptic Orthodox Church: Based primarily in Egypt.
The Ethiopian and Eritrean Orthodox Tewahedo Churches.
In Ukraine, Christmas has historically been celebrated on January 7. However, in 2023, the government officially moved the public holiday to December 25 to align more with Western traditions, though many citizens still observe the January date.
Other largely Orthodox countries, including Greece and Romania, shifted their Christmas day to December 25 to align with Western Europe following geopolitical changes after World War I. Bulgaria followed suit later, officially moving its church celebrations to the 25th in 1968.
In Belarus and Moldova, Christmas is celebrated as a national holiday on both December 25 and January 7, accommodating various Christian denominations. Different regions of Bosnia and Herzegovina and Eritrea also have holidays on both days.
Why is the new year on January 1?
January 1 was established as New Year’s Day by the Romans in 153 BC, long before Christianity. This date marked the beginning of a new term for Roman government leaders to take office. Julius Caesar retained January 1 during his calendar reform in 46 BC, as the month was named after Janus, the god of beginnings.
The exact date of Jesus’s birth is not known for certain. Christmas, celebrated on December 25, was chosen based on early Christians’ belief that Jesus was conceived on March 25, marking the Feast of the Annunciation. Adding nine months to that date results in December 25.
The year does not start on Jesus’s birthday because of how Roman politics and Christian theology intersected.
The different types of calendars
A number of religions and cultures use different calendars, mostly based on the sun and the moon.
Solar calendar
The solar calendar is based on the sun, using a fixed duration of 365 days to mark one year, or 366 days during a leap year.
The year is divided into 12 distinct months, with the English names primarily derived from Latin and Roman traditions. These names were preserved when the Roman calendar evolved into the Julian calendar and later the Gregorian calendar, which is used today.
The Gregorian, Kurdish, and Persian calendars are examples of solar calendars. Nowruz, meaning “new day” in Persian, is celebrated on March 21 each year, marking the beginning of spring.
Lunar calendar
The lunar calendar is based on the moon and comprises 354 days and 12 lunar months of 29 or 30 days, which is the time it takes the moon to pass through its phases.
Since the lunar calendar is about 10 to 12 days shorter than the solar calendar, the Lunar New Year falls on different dates each year.
The Islamic calendar is a lunar calendar, and in 2026, the start of the new lunar year, or the first of Muharram, is expected to be on June 16.
Lunisolar calendar
The lunisolar calendar combines features from both lunar and solar calendars.
It uses lunar systems for days and solar systems for months. This calendar is divided according to the phases of the moon, but is adjusted to align with the solar cycle.
The Jewish, Hindu, Sikh, Buddhist, and Chinese calendars are examples of lunisolar calendars.
