I also have this hunch that submission timing plays a role, not only on HN but other places where there's some time factor involved in the moderation system, ex

I also have this hunch that submission timing plays a role, not only on HN but other places where there's some time factor involved in the moderation system, explicitly or implicitly. My guess is you could examine this somehow quantitatively, although it might be a little idiosyncratic to specific locations.