When Communism took over Russia, many Christmas traditions were suppressed or ended, such as the feast of St. Nicholas that was held on December 6 each year. The tale of Babouschka was also temporarily suspended, and Christmas trees were replaced by “New Year's” trees. When Communist rule fell, the traditions that had been around for centuries before were celebrated once again.

Russian tradition still uses the Julian calendar as opposed to the Gregorian calendar, placing their celebrations 13 days behind ours. Christmas Eve is thus acknowledged on January 6.

Sources:

http://russian-crafts.com/customs/christmas.html

http://www.christmas.com/worldview/ru

http://www.santas.net/norwegianchristmas.htm