Extended Meeting-slot length

Hi there, I want to have the option to chose a meeting length of at least 12 hours plus, the best would be also to be able to set all day events as an option for booking page events. This would be essential for me as a freelancer in various cases.

Priority 1: Extended meeting length above 6 hours: best would be to be able to choose 24 hours

Priority 2: all day event possibility for booking page scheduling.