Disabling dates makes them unavailable for start and end dates.
Invalid dates and times can be overriden to be valid. In the following examples dates between 2018/12/13 and 2018/12/29 are invalid, except between 24th and 26th, and times between 13:00 and 20:00 are invalid, except between 15:00 and 17:00
Overriding inside invalid ranges
Besides date objects you can use date strings and moment.js for invalids.