As an elf on the shelf, it is customary to begin your elf duties at the beginning of December, when the holiday season officially begins. However, the exact start date can vary depending on the family's preferences and the specific traditions they follow. Some families may start the elf's activities as early as November, while others may wait until after Thanksgiving. It is important to discuss with your family and establish a schedule that works for everyone. Additionally, it is always good to check in with the parents or guardians to make sure they are comfortable with the idea of an elf watching and interacting with the children.