4 ms·

Do you know why we invented time zones?

• dredmorbius 10y ago
  Train crashes. 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. https://www.timeanddate.com/time/time-zones-history.html https://www.timeanddate.com/time/time-zones-history.html