One of my guests just asked me to cancel his Airbnb resavation due to unforeseen circumstances and It was more than one month notice, so I accepted his request. But my Airbnb callendar is still appearing his booking schedule as cancel status. How can I remove this status and change it to available to anyone? Many thanks for your help.
Unfortunately, that's not possible, Masaki. Never, ever cancel a booking, as hosts are penalised when they do this. It's the guest's responsibilty to cancel. Looks to me like he was trying to avoid losing the AirBnB service fee.