If I'm thinking about calling someone I'll check their IM status, not look at the clock.
If I'm going to a store I don't visit often I'll have to look up their opening hours on a map anyway. Whether that says it's 08-20 or 16-04 couldn't matter less.
And that's before getting into the even more ridiculous stuff:
> First of all, we need to straighten out some terminology. The terms "a.m." and "p.m." (ante meridiem and post meridiem) are strongly deprecated now, because they refer to the position of the Sun, not of the clock.
So use 24-hour time? Somehow the rest of the world manages just fine.
> So, you have to say "solar noon" to refer to the instant when the Sun is at its zenith, and "twelve hundred hours" to refer to the instant when the clock reads 12:00. Similarly "solar midnight" and "zero hundred hours". And you have to use the twenty-four hour clock, it's the only way to be unambiguous.
12:00 is just an arbitrary time anyway, and even now it might not have much to do with noon anyway, depending on where you live. Hell, look have a look at the arctic circle, where noon (or day/night) doesn't have much of a meaning anyway.
> Even in the best case scenario, it is impossible to retroactively scrap time zones. The past will always exist, and the people who lived there will never adopt your new standard. Nor can all of past history be renumbered. The history of timekeeping will remain exactly as complicated as it always has been, and the zoneinfo database can never be abandoned.
Do you also refuse to use epoch timestamps, because they can't represent dates before 1970? Sure, you'd need to handle zones for historical data, but that'd get progressively less relevant the further away from cutoff you get.