My best guests know who they are because they are given a traditional South African Braai. We provide them with steaks, chops and boerewors along with rolls, salads and milktart and koeksisters wihich is traditionally South African. We have even offered them traditional curry and rice as other times.
Guests know that I have strict checkin/checkout times where I personally see the guests in/out. As I have two guest houses where people are coming and going all the time, I cannot afford to be late as somebody else may be waiting to come or go and I simply cannot be in two places at a time. If they are late then they need to meet me at an alternative venue. Some guests also insist on leaving at 3am or 4am at checkout and then I ask them to drop the keys off where I stay. I used to stay up late and wake up early for late checkins or early checkouts but guests don't bother mentioning in the review so I have stopped bothering to do it.
I know that at most places where we book to go on holiday there is a late charge: R400 for 2 hours late, R500 for 3 hours late, R600 for 4 hours late.
When I have contacted Booking.com customer services to advise that a guest requested checkin time of 15h00 and is still not here by 18h00, then Booking.com has advised me that the guest has until midnight to checkin as that is the only time I can mark guest as a no show. I reckon that if a guest has not checked in by the time they have agreed to then you should mark them as a no show and not have to wait til midnight. Someone else could be looking for accommodation.
I have thought about leaving keys at a local petrol station for the late checkins or they could possibly leave keys there too for early checkouts.
I have also had several inquiries from my gate sign at 2am orr 3am but nobody can make sense out of what I am saying at that time of the morning!