The timestamp under each title seems to be the timestamp of when it was summarized and not when it was actually posted on HN. As a reader, I would prefer to see when it was posted. You already have a "updated x hours ago" at the top of the page so there is no reason to just repeat that updated timestamp on all the cards.
Oof that was a bug, just fixed! Clear your localstorage to refetch the data and the time shall be correct now.