I don't care about dates on titles in HN, but strongly care about dates _somewhere_ on any post online. Some indication of the time (range) when it was published. Even if the author doesn't consider it important it helps future readers (including the author! kinda like code comments!) answer all sorts of unanticipated questions about the post down the road. And it's easy to do. I do it all the time by reflex in my private longhand notebooks. So if you also consider this precious, I don't understand what you mean by "precious" and I have trouble translating it to some concrete ill-consequence that would preclude doing this very easy thing that might help one's readers.