Personaly, If I didnt board friends horses I would make is simple and easy to understand. 1st time its late, ill forgive but it better not be more then 5 days late. 2nd time you get a 30 day notice to leave. You have to realize people wont push you or take advantage of you when you set firm guidelines. But if you don't care or don't charge for 5 days late everytime. They will pay other stuff that don't have a grace period.
I have enough stuff to worry about and bad/ non paying boarders isnt one I want to worry about.