Ahhh. It seems to have a timestamp thing at the very top of the post, to the extreme right of where it says "Joshua Strobl joshstrobl Packaging Team".

That presently has what's probably an edit count "1", then to the right of that is the timestamp. For me, it's currently saying "19h".

When I hover the mouse over that for a few seconds the tooltip pops up with:

    2 Apr 2024 19:40

That's pretty likely the "official" submission date, no idea which timezone it's in though. Could even be localised to whatever timezone the viewer is in. :)