i'd say probably anywhere between 11 and 3 (check-out and check-in times). i think maybe once i've gone back to my hotel room around 2:30 and it had not yet been visited.
the simple thing to do is just stick the do not disturb tag in your door lock. it should be fine for a day. if you're planning on not wanting it longer than a day, you should probably dial housekeeping from your room and request it as i've heard that if they do come by and there's a do not disturb sign, they will come back at least once more throughout the day to check, so it's just a matter of courtesy.
typically speaking, if they can't get into your resort room to clean, they should provide you with a bag including fresh towels (hung on your door).
there are additional locks on your door while you're in your room so it cannot be physically opened even when someone uses a key. so with all that, there's no need to be concerned about being 'disturbed'