Christians around the world are celebrating Christmas on 7 January. Russian Orthodox, Georgian Orthodox, Serbian and Jerusalem churches celebrate Christmas 13 days after Roman Catholic Christmas.This shift was caused in the early 20th century, when the Russian Orthodox Church decided to stay on the Julian calendar instead of moving to the Gregorian calendar, like most other Christians.Russian Orthodox Christians mark the beginning of Christmas festivities with a special midnight mass. President Vladimir Putin attended a service in a monastery in Novgorod.
