8: 30am According to the business hours of Ningbo Costco, the business hours of Ningbo Costco are from 8: 30am to 20: 00pm from Monday to Sunday. Costco is the largest chain membership warehouse in America. PriceClub was established in San Diego, California on 1976, and Costco was established in Seattle, Washington seven years later. In 2009, Costco was the third largest retailer in the United States and the ninth largest retailer in the world.