I know better than most how long it takes for publishers to make a decision on a book that is reasonably well-written and therefore difficult to reject. Right now I have books at two of Australia’s big publishers. One has been there for almost a year; the other has been there for literally years. Even when a book is accepted for publication, there is a lot of editing, proofing, and maybe even illustrating to do.
This is an article about how long it takes to go from acceptance to publication.