alt Hacker NewsThanks! Digging into your link I found the explanation:
> There's one glitch that occasionally confuses people. When the software lobs a story, it displays a rolled-back timestamp—not the original submission time, but a resubmission time relative to other items on the front page. If you see a timestamp inconsistency on HN, this is probably why. Edit: if this is the kind of detail that interests you, see https://news.ycombinator.com/item?id=19774614 for a more recent explanation.
I think it also messes up the timestamps on top level replies? It's super confusing, and sometimes you see a reply that's outdated since there's been new new or discussion since, etc.