For my trader i use the term 'weeks ago', if i tell someone about the lat trade runs i made. It looks silly, in my view, if i tell them about the drinks on New London 30 minutes ago, whil beeing in NY for exapmle.
On my weapon dealer, i play in realtime.
Side note: Realism is boring. IF distances, planets suns etc. are correct in size, we all would need hours to cross a system without lanes. Even cruising to the next lane, if disrupted, isnt an option anymore. If you want realism, go out of your rooms...