Those problems already exist and have presumably already been solved for people living in the "wrong" time zone, such as western China which is completely out o

Those problems already exist and have presumably already been solved for people living in the "wrong" time zone, such as western China which is completely out of sync with the sun. So instead of having to get both the time zone and the sunlight/work hours right, we'd just have to do the latter. About store opening hours, if you travel to Singapore (very popular stopover country), you'll have to work that one out - they open much later in the morning than western countries. That's just one example - https://en.wikipedia.org/wiki/Shopping_hours https://en.wikipedia.org/wiki/Shopping_hours