I problem I see with that is date. If you are switching to UTC, the us will everyday between 2-6 pm local time switch to a new day (= date = weekday). So your workweek will be monday 9pm to saturday 4 am or so. Public holidays will be some weird time too. And problems like sheduling meetings with people in other latitudes exist further because you have to ask them for their time preferance instead of guess by business hours. (Not to say that it is impossible, but you get some inconviniences from it too)