When do newly released Ebooks get put onto the iBooks store?

You mean you preordered o the iBook Store? I don't think there is a set time of the day that it comes out. I know that when I buy a season pass to a TV show, I get emails as the shows become available. The movie preorders work this way too. I would expect iBook content to do this as well.

Nobody can tell you anything about if or when any particular book will ever appear in the iBookstore. If something you want is not there, go to one of the other stores like Kindle, Nook, or Googlebooks.

I preordered a book earlier this month in the apple bookstore. When i ordered it the listing said the book was expected to be available on a certain date. It also said they would not process the charge until the book was delivered. The day that it was supposed to be available i got an e mail telling me it was now available, and by the time i opened the obook app, it was already downloaded and installed.

The system worked fine on preorders, as long as the publisher delivers the goods.

Sorry, but no one here will know. We're just fellow users and don't know when Apple will put up any given content.

Regards.