I did a brief analysis a few years ago after shoving the HN Algolia results into Postgres. IIRC, the optimal time (for highest median score) was on a Sunday afternoon or something like that. I figured that meant that you're not competing as much for views on Sunday afternoon and will get higher-on-average points. Then you may still be around on page 1 or 2 for the Monday morning rush and get a lot more traffic.