It's on Planet X, Nibiru, so time drifts as that comes in and out of focus, gets more out of sync the greater the existential threat it poses to the world
The servers are in the UK hosted in a proper third-party data centre so should be keeping time. I'll ask if the team which deals with the servers or the server hosts can do anything about keeping time better synchronised.
I think what probably doesn't help is the time at the bottom of the page not always updating. Just looked down and that was way out of whack ... that may have been what I thought was the 'remembering time of starting reply'. Hit page refresh and it was back, though 10 minutes out.
That would seem to be a feature of the forum software so probably not a lot we can do about that.