PS @Annette230
Your check in window is your business, but up to 4pm does seem very early. Is there anybody you can rope in to do later check ins for you when necessary?
Also, I have a late check in fee for arrivals after my 3-9pm check in time. I will waive this if they're coming before 10pm, but I always remind guests when they inform me of a late arrival that there will be an extra fee involved. They can't really argue with that as it's clearly stated on the listing. I've only once had guests not pay it, even though they turned up at 1am, instead of 8pm, but I wasn't surprised really as they didn't follow most of my other house rules either! The rest have been fine about it though.