I thought about this. My watch needs to tell me (no matter were I am, by using GPS) what time are the most common for meals and what time is my meeting with the locals. What numbers it assigns to these are not material, but UGMT would make the most sense. I once made a trip south of Chicago. Got to my destination in Indiana. I could not make sense of the miles per hour I realized for the trip. Then later on I realized that Indiana has two time zones and I had gained an extra hour between Gary and Indianapolis.