It appears that the Date/Time stamps in the Device Event logs reflect local browser time, not the hub Time Zone time. What is the rationalization for this? Perhaps I'm in the minority, but my preference would be to reflect the actual hub time to eliminate confusion when troubleshooting event triggers.
Shouldn't local time and hub time be the same? Which one is accurate?
Are you looking at the hub on-location, or remotely?
I live in Pacific Time Zone, but have a vacation home in the Mountain Time Zone, where I just installed a C8 (2.4.4.135), and am currently. So, I am local to the MDT hub, but leave my PC in PDT (just cuz'). Even with a LAN connection to the MDT hub, the Device Event times are still in PDT. I switched my laptop over to MDT, and confirmed the displayed Event times switched with it.
Why would you expect anything different? That is how time zones work, times get translated to your local time. When you get an email, it is not stamped with the time it was in the time zone it was sent from, it is stamped with the time it was sent based on your time zone.
You are not asking why Hubitat does this, you are asking why everything does this, and that is just simply how things work. What would be strange is if Hubitat didn't do that.
I agree with @chrisbvt , this doesn't sound like it is working incorrectly. I would also expect this behavior given what you are doing here.
You changed the time zone in Settings/Hub Details to MST?

I would think the hub would deal internally with GMT from whatever time server it used and then present what the user has chosen as location, throwing in DST as a bonus.
Yes, I have, thanks. I guess the answer to "Perhaps I'm in the minority..." is yes... yes, I am. My argument is when I'm creating rules, the event triggers and conditions based on time use the hub time, not the browser time my PC is set to. To me, it seems logs should also reflect that same time. But evidently, that's just the way the world works.
I know not much, but you could probably use some end point command to set the NTP (time) server for the hub to be something other than what you have now (local?). At least I think you used to, lol. I'm not going to experiment.