How to transmit data of restricted dates to the datepicker?

How to transmit data of restricted dates to the datepicker?

Greeting.
Apologize for the poor knowledge of the language...

I have a question.
I need to transmit the data of the restricted dates to the DatePicker, but i can't find on the site info how to do it. I made the reservation for the sanatorium, and a visitor on the site should have see which rooms are free on a  certain date range. But how can i transmit this data to the DatePicker? And how this date should be like?

Sorry again for my poor language.