the HN mods "re-upped" this submission, which works by pretending that it was submitted later (and hence the ranking calculation treats it as new etc). It also fudges how the timestamps appear on the page. (presumably because otherwise people would be confused why a post from an hour ago has comments made 4 days ago)

On the user pages this doesn't happen and it shows the original time.

I’ve seen this with other posts in the past. I’m glad somebody else is acknowledging it. I was having a major “Mandela effect” feeling when I noticed it.