Why do citizens of USA believe the rest of the world know the offset of their local timezone labels such as “AST”, “EST”, “EDT”, etc.? Why can’t you just use UTC offset like everyone else?

Give us UTC+0 and we’ll think about it. More seriously, I doubt most Americans know their UTC offset nor how to use it to calculate the time difference. It isn’t taught in schools nor used in any public capacity. I personally use timeanddate.com with cities, not zones.

Hah! 😄 With UTC+0 at CST you’d still have to somehow relate to UTC-5 through UTC+15. You’re probably right, though. Which is sad.