Any-Growth8158 t1_jaanqnl wrote on February 28, 2023 at 1:38 AM

When it took months to cross an ocean no one really cared. Everyone just used their own local time. Most people didn't need to subdivide time that accurately. Sun comes up you work. Sun goes down work is done. Sun is at the highest point in the sky it's noon. The fact that the time wasn't the exact same as a town a several miles and hours away by foot (or horse) didn't matter.

macph t1_jab3iwf wrote on February 28, 2023 at 3:37 AM

if you're circumnavigating the globe, eventually you will care, at least a little bit.

A small bit of trivia that isn't worth a top-level comment: according to wikipedia, when Magellan's sailors returned from the first circumnavigation of the globe, they were off by a day and surprised by this.

(Also according to wikipedia, the loss/gain of a day by circumnavigators had been predicted a few hundred years earlier by Abulfeda, a geographer/historian/prince)

Any-Growth8158 t1_jab58rz wrote on February 28, 2023 at 3:52 AM

Excellent point about the importance of measuring time to determine longitude. Probably the main driver for more accurate time keeping during the Era of Exploration.

ErieSpirit t1_jac15wt wrote on February 28, 2023 at 10:09 AM

Actually crossing oceans meant you had to understand the time was different everywhere. Once Harrison came up with a clock that could keep accurate enough time so a mariner knew what time it was back at the prime meridian, mariners could determine their longitude.