One big time zone sucks only if everyone incorrectly assumes everyone else in that zone has the same sleep/work schedule, rather than letting knowledge of the o

One big time zone sucks only if everyone incorrectly assumes everyone else in that zone has the same sleep/work schedule, rather than letting knowledge of the other person's location better inform that assumption. This tactic scales all the way up to the whole world just using UTC without clocks being set differently anywhere. Instead of a time zone meaning "a zone where clocks are offset by X amount" it's replaced by "a zone where the typical start of work is X o'clock." Of course, then we have to decide if "noon" and "midnight" need to be redefined not to mean precisely 12:00 and 0:00 respectively, but instead to be used as vague ideas the way we use the vague "midday" and so forth. Edit: Or not vague per se, but calculated and looked up exactly how we do sunrise/sunset.