@Andrew2350 no, the host can't change the rules on a confirmed booking. But you will have to decide how much you care. If your correspondence becomes confrontational this will probably have other negative consequences. In your shoes I would probably let the host know that you were counting on the check-out time in place when you booked and the new time is inconvenient for you, and politely ask her to honor the original time. If she refuses, and this is a deal-breaker for you, you could call Airbnb and ask for a penalty-free cancellation.