Christmas or Christmas Day is an annual festival commemorating the birth of Jesus Christ, observed most commonly on December25 as a religious and cultural celebration among billions of people around the world.
A feast central to the Christian liturgical year, it is prepared for by the season of Advent or the Nativity Fast and initiates the season of Christmastide, which historically in the West lasts twelve days and culminates on Twelfth Night; in some traditions, Christmastide includes an Octave.
Christmas Day is a public holiday in many of the world's nations, is celebrated culturally by a large number of non-Christian people, and is an integral part of the holiday season.
The celebratory customs associated in various countries with Christmas have a mix of pre-Christian, Christian, and secular themes and origins.
Popular modern customs of the holiday include gift giving, completing an Advent calendar or Advent wreath, Christmas music and caroling, lighting a Christingle, an exchange of Christmas cards, church services, a special meal, and the display of various Christmas decorations, including Christmas trees, Christmas lights, nativity scenes, garlands, wreaths, mistletoe, and holly.
In addition, several closely related and often interchangeable figures, known as Santa Claus, Father Christmas, Saint Nicholas, and Christkind, are associated with bringing gifts to children during the Christmas season and have their own body of traditions and lore.