Hello, i have one question, what if we want go to someone flat and he check out at 12:00 and our flight is early 6:15A.M so we need check out 5:00A.M ? and host cant check out us in this time. Whats happening in this situations?
If you have already made the booking, then you should come to some agreement wiith the host as to where you will leave the key when you checkout.
The host cannot stop you checking out - you could leave the evening before if you wish. All you need to ensure is that you leave the place in good order, and ensure the host gets the key back.
No host would ever mind you leaving earlier than the check out time. That is just a "check out by" time. It doesn't mean you have to wait around until that time, same as a hotel. Just communicate well about what they would need you to do prior to leaving (eg, leave the key in a particular spot?).