A brand new Costco store is officially opening in Ontario, and it's happening much sooner than you think. After months of anticipation and a tentative "end of summer" timeline, the retail giant has now confirmed the official launch date for its Newmarket location. The store's hours will run Monday to Friday from 9 a.m. to 8:30 p.m. and Saturday to Sunday from 9 a.m. to 6 p.m. The new Costco will technically be the first in Newmarket, but the second in the general Newmarket area, joining the existing East Gwillimbury warehouse located at 18182 Yonge St. Eventually, the big box retailer plans to convert the East Gwillimbury store into a business centre, although no timeline for that transition has been announced yet.