Proposal: have a shorter way to write "global time" (or you could have, say, 4 quarter-global times), the same way we have C, F and K for temperature, then make that a more common way of communicating time.

Yeah UTC kinda does that but nobody uses it like that. Shorten it to U and it's much punchier. Also abolish daylight savings, too confusing.

If you don't wanna bias to europeans too much, use the international date line.