On the landing page for books on the O’Reilly ebook platform where you see the jacket, author info, publication date, etc., there is a “Time to Complete” section that sometimes confuses students. Here is a screenshot of the landing page for one book that says “5h 13” in the “Time to Complete” section:
All that “Time to Complete” means is how long it is estimated it will take the average reader to read the whole book. It does not mean that the book can only be used for 5 hours and 13 minutes. There is no loan period for O’Reilly ebooks and they can be accessed by more than one user at a time.