Christmas season begins on December 1st, with the start of Advent, the season of waiting and preparation for Christmas. During this time, many people start putting up their Christmas decorations and getting into the holiday spirit. The four weeks of Advent lead up to Christmas Eve on December 24th, which is the night before Christmas. On Christmas Day, December 25th, the Christmas season is officially underway, and families and friends come together to celebrate the birth of Jesus and exchange gifts.