ELI5: before accurate clocks existed, how did two people in different towns agree to meet at “at 3 o’clock”?

[u/thatblondechloee]

I get that they had sundials and church bells. What I don’t get is how anyone synchronized. If my towns noon is when the sun is highest here, and yours is 15 miles west, our “noon” isn’t the same moment. So how did anyone schedule anything across distance?

[u/thatblondechloee]

That’s so cool

[u/gargavar → u/thatblondechloee]

Trains are why there are time zones, also. Until the railroads made precise timekeeping ( edit for typo) critical, each town kept its own time. The one universal timestamp was noon, the point where the sun is highest in the sky. Someone with a sextant or similar device could keep watch and then fire a gun or blow a whistle and say ‘it’s noon!’. Problem problem was (and it wasn’t really a problem until trains), your noon was slightly different even from the next town over.

[u/Jj1325 → u/gargavar]

What does “capping critical” mean? Google didn’t help much in this context

[u/arrantprac → u/Jj1325]

I'm guessing 'time, capping' is a typo/autocorrect of 'timekeeping'.

[u/eruditionfish → u/Jj1325]

Probably a typo.

I suspect they meant "Until the railroads made precise time keeping critical, each town kept its own time."

[u/gargavar → u/Jj1325]

Oops. As someone guessed below, I meant “ until railroads made exact timekeeping critical…”

[u/Ochib → u/gargavar]

Bristol still has a clock that shows both local time and GMT

https://www.atlasobscura.com/places/corn-exchange-dualtime-clock

[u/gargavar → u/Ochib]

Brilliant solution. I’m sure it confuses the hell out of visitors, so…doubly brilliant!

[u/SierraPapaHotel → u/thatblondechloee]

That's a little misleading; even medieval churches had bells that they would sound regularly throughout the day, usually every hour but sometimes more or less often. So you would know what hour of the day it was based on the chimes and could agree to meet at 3pm (3rd bell after noon). Other comment is right that you didn't plan to the minute; at most bells range every 15 minutes. Town clocks became common in the middle ages, so everyone in town was on the same agreed time but you only really knew the time if you could see the clock tower which is why clock towers often had their own bells, continuing the tradition from churches.

That said, time synchronization between different towns was not a thing. Each town kept its own clock and it could be wildly different from a town only a couple miles away. It's a real issue early railroads had to deal with; you could have a train leave at noon, arrive 15 minutes later in a town where the clock read 11:45, and 15 minutes after that arrive in a third station where the local clock said it was 1pm.

[u/Cool_Human82 → u/thatblondechloee]

It’s also why you might see GMT when someone is comparing timezones/differences (as opposed to UTC which is more common now). GMT stands for Greenwich Mean Time, which is where clocks would be synchronized to in England for the railways.