SOLUTION for Calendar Overlays with modern SharePoint list

Hello

You can create overlays from different calendars based on SharePoint List (calendar view).

The trick is to create a page and add a webpart: 

Workaround 

(1) Create a new Page  

(2) Add a EVENTS WEBPART on that page it will also create an events list

(3) Delete that page  because you do not need that list.

(4) Now create two new lists like CAR1 and CAR2 and add the custom columns: "Start Date" and  "End Date"

(5) Use the events list created by the webpart from step (2)

(6) Edit the page by using SETTINGS >> EDIT PAGE

(7) Select the calendar webpart and on the ribbon tab the CALENDAR tab and click in the ribbon on "Calendar overlays"

(8) Add a new overlay and choose the color, the list (before refresh) and do it for all other lists with calendar view ;)

(9) The only problem for me was, that I cannot use a content editor webpart to add text on top of the calendar you need to use a picture.

(10) Thats it ;)

I hope it will somebody yet...

Cheers

Michael Damaschke