The book list doesn't ever refresh spontaneously, which would be required to notice that time had passed. Something must happen to make calibre redisplay the list. That "something" doesn't need to be a change/edit. In your case, I am sure that any of the following would cause the list to refresh. This list is certainly not exhaustive.
- Search for something. Perhaps something like "title:true" that will find all the books in the virtual library.
- Change to a different (or no) virtual library then change back.
- Look at the device view then come back to the library view.
- Edit metadata (multiple) and press OK without making any changes.
- Change to the cover grid then back to the book list