The math would've been a lot easier if GMT+0 had been somewhere in the Pacific ocean. Going from +1 to -7 is a lot more troublesome for most people than from +11 to +19.

Well, it would just move the issue to Europe wouldn't it? If Europe became a -10ish time zone, they would be the one having to go from +11 to +19.

Yeah, it would be nice if they made GMT the same as the international date line.

The international date line is where you go from GMT-12 to GMT+11 or something similar.

So, no matter what time zone you pick as the reference, by definition the international date line is 12 hours away from your reference.

Except where it's -10 or +14 hours away from reference due to jogging around countries or island groups.

See:

https://www.timeanddate.com/time/map/

Yeah it zigzags a bit but it hovers on the two sides of +/-12, placing it around 0 would mean half the world operating on a work week that is shifted by one.

Sure, but I work across three timezones, and I can glance up to the top-right of my computer and see all three at a very quick glance, as well as knowing when people are likely to be having lunch, whether it's early or late for someone, and so on. I'm also now quite used to "Jerry gets up early his time" for certain coworkers.

I guess you could potentially have some sort of graphic to show the same thing for sunrise vs sunset ... but as you point out, the maths needs to be done either way, so why get rid of a system that works pretty well?

DST is the real enemy here.