The Elf on the Shelf tradition typically starts on December 1st and ends on Christmas Eve. On the first day of December, the elf comes to a child's house and hides somewhere in the house, watching over the child to make sure they're behaving. Each night, the elf moves to a new hiding spot and reports back to Santa on the child's behavior. The elf usually stays until Christmas Eve, when it returns to the North Pole with Santa.