Many Orthodox Christians who follow the Gregorian calendar — including some Russians, Greeks and Serbs — are celebrating Christmas Day on Monday.
For those who follow the Orthodox Christian faith, Sunday was Christmas Eve, which marks epiphany for Christians who follow the Julian Calendar. Epiphany is when the three wise-men are believed to have arrived at the manger in Bethlehem.
The traditional Christmas Eve dinner was meatless 12-course meal for the the 12 Apostles.
While many Orthodox Christians celebrate on Monday, it is important to note that some groups of Orthodox Christians celebrate it on one of the days around Jan. 7.
For example, many Armenian Orthodox Christians in Canada celebrate Christmas on Jan. 6.
Orthodox Christmas is not marked by a national holiday in Canada, although Orthodox Christian churches are usually busy around this time of year.