If you use SimpleBills through your property, then yes! Residents are responsible for utility usage through the active lease term regardless of your move-in date.
If you use SimpleBills on your own and the utilities are in your name or a roommates' name, then it depends on when your utilities are set up. You will receive your first bill after your service start-date when your utility accounts are successfully linked. If your roommates give unanimous consent to remove you from a bill, the bill could be divided between the other roommates.