Timezones and Mindstates
OK. You start in France at latitude 45. That is the south of the country, and we'll say that you are due south of Greenwich. Just so you know, I'm writing this whole thing with the map open big, so you should probably read it that way.
This is only the very beginning of the trip, and things are already weird. The UK is the only county in Europe that both has and should have GMT. The other countries that should also have GMT, France and Spain and Norway, do not. And the only other countries that do have GMT (Portugal, Iceland, and Ireland) are mostly or entirely in GMT-1. If I woke up one day to find that everybody except me was insane, it would cross my mind that maybe I'm the one that's crazy. These are the thoughts that the UK should be thinking.
Anyway, you are still at 45 degrees north, halfway up to the pole, and you starting flying east towards Russia, as the crow flies, but farther and a lot faster. Its noon in Greenwich, and lets say that you are going fast enough to circle the earth in a few seconds.
We haven't moved yet, so its 1:00PM where you are, it should be noon, but its 1:00, until you hit Romania and it becomes 2:00PM. 2:00 PM starts early and ends early, you get about half as much 3:00PM as you should and it jumps to 5PM. Only some parts of Russia are having 4:00PM right now. None is this is wierd. In Kazakhstan you increment predictably to 6PM, which you enjoy an hour early in GMT+5 Halfway through 6PM you find yourself in China at 8:00PM, even while its still five in some places (or five-and-a-half in India). This isn't weird yet.
China is big, and it has one timezone, so you don't leave 8 until almost nine. That makes a lot of sense, right? Back on track. Very sensible. Well, you leave 8 and go into 10:00PM in Russia. That is less sensible, but forgivable. Japan is the next country past Rusia, and it appreciates the utility of 9:00PM. So when you reach Japan, having stayed at 45 degrees north the whole time, and traveling only directly east, you go Back into 9:00PM. When you leave, you jump up to 11:00PM in Russian, go back in time Again to 10:00PM, then up again to 11:00, then to midnight, but instantly to midnight of the night before, just west of mainland Alaska.
All that backwards stuff happened quickly, just between GMT+9 and GMT+10. Imagine driving from Chicago from New York. But instead of going from 4:00PM to 5:00PM, you go 3:00, 5:00, 4:00, 6:00, 5:00. You can put equal blame on the Russians, Chinese, and Japanese.
The Pacific is boring/sensible, switching when and where you might expect, excepting the 24 hour leap backwards in time. In the US, 8:00PM (PST) is truncated, and 6:00PM (Central) takes (a little more than) its time, but the rest of the trip, around to where you started, is sane. There is one more exception. The whole timezone system is built around GMT, but you never actually entered GMT the whole trip. You skipped noon---no lunch. That might be wrong: it depends on what time it is over an ocean if (a) you are in GMT+0 (where it would be noon) but (b) within the waters of Spain and France (where it is 1:00PM).
I found out about this craziness because I'll be in Sapporo, Hokkaido, Japan, the big empty island in the north of Japan that looks like a birthmark. I don't have any friends just east in Vladivostok. But I do have family in Manila. The one is close to being due north of the other. But, while calling my family in Manila means subtracting an hour (like you'd expect), calling a friend in the other will mean adding an hour. That is backwards.
Between Greenwich and Westphalia, there isn't room for both your time and your sanity. Actually, I don't really believe that. I bet it would be even weirder if we cut things the way that the folks in Greenwich originally intended---in terms of longitude rather than by national preference.