For the tl;dr crowd, pulled from that article (although I highly recommend you just read it):
Abolishing time zones brings many benefits, I hope. It also:
- causes the question "What time is it there?" to be useless/unanswerable
- necessitates significant changes to the way in which normal people talk about time
- convolutes timetables, where present
- means "days" are no longer the same as "days"
- complicates both secular and religious law
- is a staggering inconvenience for a minimum of five billion people
- makes it near-impossible to reason about time in other parts of the world
- does not mean everybody gets up at the same time, goes to work at the same time, or goes to bed at the same time
- is not simpler.
As long as humans live in more than one part of the world, solar time is always going to be subjective. Abolishing time zones only exacerbates this problem.
Now, remove that bit of metadata and we need to figure out how to encode/transmit it again. At the end of the day, we just recreate time zones, with the added downside of removing a common language we have while traveling - Visit SF from the UK and not only are you jetlagged, but you need to remember that every time of the day you're used to needs to be shifted by 8 hours. - and just... talking to people in other time zones.
Right now, if you post a story on HN about needing to get up for work at 4:30am, everybody will understand: this person gets up for work really early! Move to UTC and it means nothing.
(I'm not arguing in favor of switching, just pointing out that we already have the descriptions for times of day)
Pedants that were concerned about the fuzziness of such words could hound the speaker for UTC.
"I woke up a few hours before the roosters' crow to catch a flight."
It would be awkward to say that today, but potentially less so in some alternate-dimension universal time zone world where it could be a common idiom for "wee hours of the morning". Hours would still have meaning, people at least have the thought that "roosters crow at sunrise". So you got up a few hours before sunrise, whenever that time was.
Time zones are a great example of complexity intrinsic to the problem. You can't get rid of such complexity, just move it around (or alternatively make your solution less useful).
Getting rid of time zones does simplify time calculations for a computer. But it increases complexity elsewhere and makes computers less useful.
This isn't all that complicated. Pick some astronomically-based event, say when the sun is at the zenith on equinox, and tie local time to that. Then, given that you have coordinates for every significant place on earth, it is an easy computer calculation to calculate the delta of time to where your uncle was sleeping.
Similarly, the offset to UTC is trivially available.
This is a calculation that ham radio operators, among others, already use to know what UTC the sunset or sunrise is (these are interesting times due to ionosphere changes around those times) at some random distant place far away, say Vanuatu.
China already tried getting rid of time zones, and even though it's only 5 time zones wide it caused enough issues that far western provinces use their own unofficial local time: http://www.theatlantic.com/china/archive/2013/11/china-only-...
Note that this has the side effect of automatically making it so the extra daylight during times of the year with more daylight come at the end of the working day, without the need for daylight savings time.
Seriously.
Trains presented the first time that 1) humans could travel at a sustained rate above about 10 mph, and 2) presented roadways on which it wasn't possible to spot oncoming traffic and decide, at any point, to simply pull to the side to let it pass.
There was also the matter of coordinating service with local pick-up and drop-off, and whatnot.
So now you had a requirement for all points along a linear track to actually agree on the answer to the question "what time is it now?"
"Local noon" was no longer an adequate solution, or at least, it wasn't adequate with the means available at the time for computing offsets between your local noon, my local noon, and Train Time.
Railroad engineers (train drivers), track switching controls, and other elements also had to be, or could be, coordinated. Uncoordinated switching leads to packet collisions, or in this case, literal train wrecks. Which are messy, bad publicity, and discourage business.
Hourly offsets were reasonably close to solar time (generally no more than 30 minutes off), and abstracted enough complexity that offsets could be calculated (a given train was unlikely to cross two time zones in a day).
This happened in 1883.
It has to be better than 9am is breakfast, noon is lunch, and 6pm is dinner; in that it has to be short and memorable.
The time of an event that happened needs to just be UTC; period.
The time that something is planned might not be an event, but could be a relative reference.
What does that even mean?
The only reason to use UTC is so you can compare timing of geographically diverse events easily (plus things like daylight savings). Local time is still local tmie.
Clearly it worked and no one uses the old system anymore. <irony off>
For me timezones are OK. They are a cultural construct developed to accommodate the custom of counting the hours from sunrise (later midnight) and higher numbers meaning later in the day.
Not every sociocultural construct is bad just because it causes us code monkeys some trouble.
And believe me. Trouble it causes day in day out to me.
So how do you live? ;)
Minor: Los Angeles doesn't have a constant offset to UTC. But it changes rarely enough that it's easy to absorb the inconvenience.
Major: if he was using Los Angeles time internally, he'd have all the same problems when interacting with anyone else. Using UTC internally, he still has those for counterparties that don't use UTC, but they disappear for counterparties that also use UTC. Using UTC is a strict upgrade in terms of interacting across "real changes in time".
When I interact with people in a different time zone, I like to use their time, because I figure the odds of them messing up when using their own time are low. But if I didn't do that, I seriously doubt they would have more difficulty with my proposal "let's meet at 04:00 UTC" than with my proposal "let's meet at 12:00 pm my local time".