Cornerstone Primary Healthcare. Home Forms Hours. Mon 8:00 am - 5:00 pm. Tue 8:00 am - 5:00 pm. Wed 8:00 am - 12:00 pm. Thu 8:00 am - 5:00 pm. Fri 8:00 am - 3:00 pm. Sat Closed. Sun Closed Have an ID and password? Click here to sign in Here to view a fax? Click here to view.