Thank you all for your help!

Thanks for the sample. It does exactly what I expect.

What is it compatibility level? Does it work on SQL2012?

yes I know, but some clients still use version 2012... so I cannot use it

Cool, thank you!

To make a long story short...
Tried all kinds of string encoders on the sql command before execution but that did not work.
But if I save my command to...

I suspect that when writing the command to the log file some sort of correction or formatting happens so that the command is correct when copy/pasted into SSMS???

you have to use nvarchar(2), NOT nvarchar(1)

All right, with the HAVING clause it works like it should.
Thanks

Chris, this returns also the unwanted 3rd row

Yes, this works like I want it!
Thank you so much.🙂

NULL    2018-01-01 12:00:00
2018-01-01 20:00:00    2018-01-02 08:00:00
2018-01-03 08:00:00    2018-01-03 08:00:00  This row should not be there (for my result)
2018-01-05 06:00:00    NULL

Good remark, but when there are adjacent bookings, where "till" date from booking 2 is same as "from" date of booking 3 then I also get an unwanted row (row...

Cool...
But when there are overlaps, the result is cot correct.
Please try this:

declare @t table(dBookedFrom smalldatetime, dBookedTill smalldatetime)

insert into @t
values('20180101 12:00',...

Thank you very much.
Will test it and keep you posted...

The more I examine my issue, the more complex it gets and i am starting to think there is no solution for this.
Here I have 8 rows, each row...