Disable booked dates on a pop up calendar

I am trying to making a booking tool using [login to view URL] I want to disable the booked dates on pop-up calendar. On the attached file, have a look at line 17 which blocks out weekends. This line you need to replace with your code to fetch booked dates from a PHP file so those days are blocked out from the the pop-up calendar. var valid = !([login to view URL]() == 0 || [login to view URL]() == 6); //disable saturday and sunday PHP file does not need to connect to database. As much as below is enough. $booked_dates = array('2020-10-05', '2020-07-20', '2020-08-10'); echo json_encode($booked_dates);