The regular store opening hours are as follows:
M-F 10:00am - 8:30pm
Sat. 9:30am - 6:00pm
Sun. 10:00am - 6:00pm
Hours of operation might change, so to be sure to get the 100% correct hours, please checkĀ costco.com.
Costco, 22330 Hathaway Ave Hayward, Hayward, California 94541
Phone: (510) 259-6600