Again, I challenge you to provide any evidence whatsoever of a public library system in operation in the U.S in 1963 that routinely recorded the actual return dates of books that were returned on or before the due dates. Unless you can, I am finished with this discussion. Period.
I'm sure you are. Because none of that is the slightest bit relevant to how Mosk got his "return dates". It's all one big trip on the speculation bus.