Costco warehouses are open weekdays from 10 a.m. to 8:30 p.m., Saturdays from 9:30 a.m. to 6 p.m. and Sundays from 10 a.m. to 6 p.m. The Costco website lists the hours for its business centers as well as the holidays during which its warehouses are closed.
Costco is a membership warehouse club that sells brand name items at wholesale prices. It sells a variety of items, including groceries and other household products, clothing, furniture and electronics. Members can shop online or at any of its locations across the United States. It offers full refunds for every product it sells. Additionally, it refunds the annual membership fee upon request.