[oofabz]

It would be confusing having the day change in the middle of the afternoon. I'd get to work on Monday but leave on Tuesday. If I told someone I'd do something on Wednesday, what would that mean? All the solutions I can think of are complex, thus negating the benefit of switching to UTC.

I like the "Zulu time" system used by pilots and the military. A time like 12:30 is understood to be local time, while 0730Z is unambiguously UTC.

[gooderlooking]

It's only confusing because it's different from what you've been doing your entire life. The solution (hypothetically, as this will never happen in our lifetime) is a different paradigm. You could say, "I'll get that to you by COB Wednesday", and it's understood by custom that "Wednesday" means "the workday that began on Wednesday". But more likely is that you'd say, "it'll be on your desk by 06:00 on the fourth." Speech patterns would adjust.

[ngpio]

> Speech patterns would adjust.

It isn't even hypothetical. The speech patterns of all English speakers who spend a significant amount of midnights awake have adjusted precisely like that.

There was a lovely looped animation of the world's online activity over the course of 24 hours. Can't find it right now, but I'm pretty sure it was on HN. It really exemplified how daytime no longer relates so much to the presence of the sun in the sky as it does to the level of physical alertness and electronic communication. High noon is more like the median longitude of human and network I/O than it is solar noon.