If you want to know if your store is open these days, you can contact it.
These opening hours don't take account of public holidays and of Sundays. You can also check if Costco Sunnyvale is open on Tuesday by calling it.
Usually Costco Sunnyvale is closed on Sundays. Careful, stores-locator.com is a participative site, where anyone can indicate opening hours. If you see any mistake, please contact us.
