Locally my source would be biased because of course I live in a country where the time actually is called GMT for half the year, so from their point of view wha

Locally my source would be biased because of course I live in a country where the time actually is called GMT for half the year, so from their point of view what's going on is that there is global time and it's their time. History of imperialism you know, that's why there's so much of other people's stuff in our museums. If there really wasn't global time, this couldn't work, time zones, all of that jazz won't work if you have a system where relativity matters, for example enormous variation in height above sea level, a particularly enormous planet or very fast spin. Or if your perceptual scales are very different, but for us, here, there is global time.