In 2021 there was a website thehtime.com. It had the best concept for dealing with timezones.
https://web.archive.org/web/20211022024626/https://thehtime....
https://web.archive.org/web/20211022024626/https://thehtime....
ZA:03 ZB:23 ZL:55 ZI:12 ZO:08
would work greatly for me
I like the concept of a global time that maps to local time, and while I am unconvinced that Latin letters are the best way to do that, I can’t think of a better way. It’s either letters of some sort, symbols, or names, and none of those sound good.