How to make free date range in google forms response?

Question

Google Apps Script

Good time everyone!
In short, the task is like "doctor's appointment".
I need to select free dates in the form, and users already select a date and time from the available range. Those. if user 1 selected 11/20/2019 11.00-12.00, then that time should be inactive in the date-time-picker on the form.
Question: are there ready-made Google add-ons, or has someone solved something similar (through a standard set of functions in google.forms or google apps script).
If you cannot do without GAS, then I will pick it.
All the best

Answer 1

Use data validation in the date/time picker. Form a list of those that are minus those that are busy . Data validation update can be hung on onEdit (event). And there will be a couple of service columns - all slots and free slots.

Answer 2

And for those who are not at all literate, you can script to the studio))) I am very grateful)))