It is an annual festival commemorating the birth of Jesus Christ, observed primarily on December 25th as a religious and cultural celebration among more than two billion people around the world.  A feast central to the Christian liturgical year, it is preceded by the season of Advent or the Nativity Fast and initiates the Christmas season.  Christmas Day is a public holiday in many of the world’s nations, is celebrated religiously by a majority of Christians, as well as culturally by many non-Christians, and forms an integral part of the holiday season centered around it.