[SamBam]

I find it insane that there are otherwise-smart people in the world that want to abolish time zones. For example, this NY Times article. [1]

In includes the most bizarre history:

> A century and a half ago, time zones didn’t exist. They were a consequence of the invention of railroads.

... and goes on to describe that it's suddenly so confusing and laughable that when it was 7:00 in New York, it would now be 8:00 in Chicago and 5:00 in San Francisco.

But what on Earth did the writer think the time was in San Francisco before there were time zones?

Before there were time zones, everyone synchronized to local noon. The result was much more fine-grained "time zones." What time zones did was to actually flatten those difference, leading to fewer time zones, because now suddenly the time in Maine was the same as the time in Michigan, despite being at completely different longitudes.

1. https://www.nytimes.com/2016/11/06/opinion/sunday/time-to-du...

[inglor_cz]

> The result was much more fine-grained "time zones."

That is true, but it did not bother anyone, because fast long-distance communication either did not exist or was very limited (e.g. smoke signals) and syncing of clocks wasn't necessary in everyday activities; for a medieval person, the idea that clocks in Vienna and Prague MUST be synchronized would be as strange as for us the idea that everyone in the same city should have their breakfast at the same time. It just did not serve any obvious purpose.

There are only two exceptions I can think of.

a) people doing astrological horoscopes for someone who was born in a different place (a big thing among some nobility and royalty) would probably be bothered a bit by the time difference,

b) armies trying to converge on the same target at the same moment.

[Piskvorrr]

...didn't bother anyone until railroads entered the equation: astrology did take the difference into account, armies didn't move quickly enough to notice it: just keep adjusting to local time every day or so (even on horseback, any tactic is far more dependent on physical limits, so you're coordinating on the order of minutes, not milliseconds).

For railroads, even at 40 kph, an east-west train would be subject to time shift (not in the Lorentz sense, it would just keep switching "timezones" too quickly). Given that the primary security element was "this train is supposed to pass this set of switches between this and that time and wait there, else it risks colliding with that other train running opposite," both accurate timekeeping and geographically wider timezones were needed (as in "the railroad will use its own time, Prague's lunchtimes notwithstanding").

[SamBam]

> That is true, but it did not bother anyone

Time zones were implemented in the United States in 1883. This was well after the use of telegraphs had become widespread, and after the invention of the telephone. While the telephone would not by able to make coast-to-coast calls for another few decades, the idea of communicating with people in other cities was already becoming commonplace.

My point was that the "messy" system the Times article describes would already have seemed reasonable to everyone, who already knew that people in other cities would have different working hours. What annoyed people was the "flattening" of the time zones, making it such that all the cities had to now synchronize their clocks to railway time, no matter what their local noon was. But this is the opposite of the point that the "one global time" advocate thinks he's making.

[WorldMaker]

Some extended timezone databases even have tried to collect historic city timezones from before the railroads, most often to the nearest 15 minute offset, but sometimes even minute specific offsets. It's interesting to explore those.

On that Michigan versus Maine thing, as someone in a city that historically was -0045 from its current timezone, I feel it interesting to point out that DST is closer to local noon than "Standard Time" in the city, versus that cities that define the other edge of the time zone and have local noon closer to Standard Time noon. (Our hour-wide time zones make the question of DST versus Standard Time much more complex than just picking one or the other, when talking about abolishing DST or standardizing only on DST.)

[amalcon]

For some evidence of this, consider that sundials have existed since about 1500 BCE. The existence of such a device easily disproves the notion that the "current time" was ever the same globally. Even mechanical clocks would obviously need to be set such that they would agree with a sundial, or the reading of the mechanical clock would be useless in a world where others are using sundials.