No, Seventh-day Adventists do not celebrate Christmas. The reason for this is because they believe that Christmas is a pagan holiday and that it has become too commercialized. Instead, they celebrate a different holiday called "the Advent" on the fourth Sunday before Christmas. This holiday focuses on preparing for the second coming of Jesus Christ and celebrates the birth of John the Baptist. They also have a tradition of giving gifts to children on the first day of the new year instead of on Christmas.