We always release our titles as pre-orders before the actual arrival of the books. That allow us to know more properly how much copies we need to print to meet the demand for them.
The shipments are made once the books arrive, so the information that this website provide to you about the transit time may NOT be accurate, as calculates the transit time assuming that the products are already available in stock, which may NOT be the case for the book(s) you are buying.
We always inform the terms in RED at product's description. Make sure you are aware of all the times.