I just did post an answer to thread, and it appeared with right time, but at yesterday, not today!? And not at top of forum!
Then I remembered about answer I made earlier today, and which I din't see anymore. I looked for it at bottom of page, and there it was - with a date from yesterday!
I checked my Windows settings - the date and timezone were right. I logged in my work computer via VPN and checked this forum - there was exactly same situation as at my home computer.
Edit. When I look at time of this post, it shows Today, 12:19 AM. My real time is currently 23:21, i.e. it was 23:19 when I posted this!