In Russia, Christmas is annually celebrated on January 7th, thanks to
the Russian Orthodox Church that has made it an official holiday in the
country. Previously the occasion was observed on December 25th in the same way
as it was in the rest of the world, complete with Christmas trees and Christmas
gifts. But after the 1917 Revolution, Christmas was banned throughout Russia,
along with other religious celebrations. It was much later, in 1992 that the
holiday began to be openly observed again. However, the church in Russia still
uses the old Julian calendar, which is 13 days behind the Gregorian calendar
used in the Western nations. This is why Christmas is celebrated in Russia on
January 7th.
Today, Christmas is celebrated in the country with the faithful participating in an all-night Mass in Cathedrals. The main religion in Russia is called Orthodox. The Russian Orthodox Church is more than one thousand years old and most of the Christian population of the country belongs to it. In Russia, many people don't eat meat, eggs or milk from a few weeks before Christmas and it is customary to fast until the first church service on Christmas Eve is over.
In the Orthodox tradition nothing is eaten or drunk on
Christmas Eve until the first star appears in the sky. The star is symbolic of
the great star that led the Magi to the newly born Christ. Once the first star
has appeared in the sky, the festivities begin with a Lenten meal – meaning
meat or dairy products are excluded.

Hope there are no more questions remaining about Russian Christmas.
Merry Christmas to all russians !!!