I offer no argument that authors and publishers should title their books as they please. However, in this particular case, I take strong exception. Is this a book about javelins? While 'half-light' might be recognized in some countries as having descriptive meaning, to me, it does not. I would urge the publisher to use a plain descriptive title. As it is, this title conveys confusion and would be difficult to find via internet search.
In my opinion, it is a nightmare from a marketing standpoint. Lately, Amazon search is offering a brief descriptive text along with the book listing. This, it appears to me, to untangle titles and get to what the book is actually about.
Scheduled for 6 October.
https://www.amazon.com/Javelins-Half.../dp/1472875265
Usual disclaimer,
Ed