How do you calculate days?
I know banks say Monday to Thursday is 4 days but what is one day? If somebody wants to borrow something for 4 days is that Monday to Thursday? Is 3 days Monday to Wednesday? Is 2 days Monday to Tuesday? Is 1 day Monday only or Monday to Tuesday? I know it's easier to work out if people talk in hours but I don't think that's relevant if they are talking in days.