Why are all of my dates grey out

I am not able to book or register online the dates are all gray out.  Please help this is not good for my business. I tried the edit and it is not working 

I tested your form here https://www.jotform.com/51316169708155 but I could not reproduce the problem. I am able to select dates in the Date Picker field.

Is this the form you're referring? If not, which form and specific date fields that are not working?