Bloomsbury Publishing kept Harry Potter and the Prisoner of Azkaban off the bookstore shelves until 3:45 P.M. (when most schools are out) on its release day in 1999. (Little did they know that the title character would himself skip school, for an entire year, in Deathly Hallows!) Even though this was just the beginning of Potter-mania, the company already recognized the impact the release would have truancy in Britain.
The first two Harry Potter books had already sold over 800,000 copies, and Bloomsbury was prepared for their biggest release ever (at the time). While they had planned on selling 157,000 copies that day, they wanted to minimize the impact that the influential book series would have on classroom attendance. Thus they were able to avoid the ironic circumstances of kids skipping school in order to read!