It is not uncommon for a property owner to "live" in the property during vacant periods between renters. Especially when the rental may be several hundred miles from the owner's primary residence. Days spent living in the property for the primary purpose of preparing the property for the next renter and making it move in ready again, do not count as personal use days.
Vacant periods between renters counts as days rented, provided the owner did not live in the property for one single day during that period as their primary residence, 2nd home, vacation home, or any other type of "personal pleasure" use.
