While several countries are getting ready to return to work after New Year parties, celebrations are just beginning in others. Orthodox Christian communities, including Greek Catholics and Coptic Christians, around the world are preparing for Christmas, which they celebrate on Jan. 7, nearly two weeks after the Dec. 25 festivities.

Christmas is observed on Jan. 7 by 15 different Eastern Orthodox churches. Nearly 39 percent of the total number of Orthodox Christians in the world live in Russia and around 85 percent of them choose to celebrate Christmas in January.

The difference in dates is a result of the calendar Orthodox Christians follow. These communities follow the Julian calendar, dating back to 46 B.C., according to which Christmas falls on Jan. 7. Also called the Russian Orthodox calendar, this was devised by Roman leader Julius Caesar.

Meanwhile most of the West follows the Gregorian calendar, also called the “Western calendar,” introduced by Pope Gregory in 1582 to correct mistakes in the Julian calendar.

While Orthodox Christian communities follow the Julian calendar, their country’s government doesn’t necessarily do the same. For example, the Russian Orthodox Church follows the Julian calendar but the Russian government functions as per the “Western calendar.”

Orthodox Christmas 2014 A child wearing a Santa Claus costume lights a candle inside the Church of the Nativity in the West Bank town of Bethlehem during the Eastern Orthodox Christmas, Jan. 6, 2014. Photo: Reuters

Communities observe different traditions in celebrating the season. Many Orthodox Christians, Greek Catholics and Coptic Christians abstain from consuming meat and alcohol in the 40 days leading up to Jan. 7 and even fast on Christmas eve, Jan. 6. Many attend Christmas eve service usually held in the evening.

Communities is Russia and Ukraine consume a 12-course meal, free of dairy and meat products, on Christmas eve. The 12 courses draw a parallel to the 12 apostles chosen by Jesus Christ. Then on Christmas day, people go out carolling.

In Ethiopia, communities celebrate with church services and sporting events and in Serbia, people hunt for an oak branch to decorate their homes with.