PetSmart stores generally close at 9 PM from Monday through Saturday and close an hour earlier at 8 PM on Sundays. This applies to both store hours and grooming hours. On Saturdays, the closing time is 9 PM. However, specific store hours may vary by location, so it is advisable to check the local PetSmart store hours for confirmation. For example, the PetSmart in Etobicoke, Ontario, stays open until 9 PM on Saturdays.