Your examples indeed show common problems with several approaches when place is coupled to a time and then proceed to ignore the place (of meeting or user) when

Your examples indeed show common problems with several approaches when place is coupled to a time and then proceed to ignore the place (of meeting or user) when converting times. I should add that where we store UTC that concerns a place, we also know/store that place in lat,long (or anything that resolves to this) and use that to show it in any timezone, to any user in any timezone, ..even in any era (yes places can change timezone).