I learned this today. Standardized time and time zones weren’t needed until rail travel became popular in the 1850s.
Having international time zones seems common sense to us these days. How can you conduct business in New York from London if you don’t know what time it is there? And knowing how many hours ahead or behind we are helps us understand why we have jet lag.
However, these ideas are modern ones. They come in a world where fast international travel and communication are the norm. Before the 19th century, travel and communication went at the same speed. If you were doing business in New York from London, you would write a letter, give it to someone on a ship, they would sail across the Atlantic, deliver your letter, the recipient would write a reply, give it to someone on a ship, who would sail across the Atlantic, and give it to you. Inside of a month if you were lucky. There was no need to know that New York is 5 hours behind London.
That is not to say that people had no concept of it. The idea of longitude had been around since the Greeks and people knew there is a 4-minute time difference between each longitude. If it is noon at Greenwich (which is at 0 degrees), it would be 4 minutes later at 1 degree west. This was used extensively for navigation. If you know the time in Greenwich and you know the time where you are, you can calculate your longitude.
This necessity was the driving force behind the invention of accurate clocks that don’t need a pendulum. You can’t use a pendulum clock on a ship because the rolling of the waves messes with the time. John Harrison built an accurate chronometer that could be used on ships in the 1750s. However, this didn’t necessitate time zones.
Two inventions caused the need for standardized time and time zones. Trains and the telegraph.
The first railway line in the UK to use steam locomotives, the Stockton and Darlington Railway, opened in 1825. When people saw how profitable and useful it could be, the rail networks were expanded. In 1830 there was 157 km of railway line and by 1850 there was 10,655 km. They were built to haul freight, but they became more popular as passenger trains.
And this expanding rail network brought a problem to light. As we have discussed, with every one degree of longitude west, you lose 4 minutes and with every one degree of longitude east you gain four minutes. Since the invention of clocks, people have set their clocks by the sun where they live. A clock set in London will tell a slightly different time to a clock set in Oxford which is five minutes behind London time. That is not a problem if you never leave your area. It is a problem if you are trying to make a railway timetable for an emerging national network. You cannot reliably run trains if you have to work out the local time at every station your train is going to go through. However, for the first few years, that is exactly what they tried to do. There was no way for people to accurately know the time in other towns, so tables were supplied by the train company to convert local times to London times. This wasn’t straightforward.
Then the second invention came along and solved the problem. The first commercial telegraph system was installed in Britain in 1837. It didn’t take long for people to realize that along with all of its other uses, it could be used to send the accurate London time to all other cities. It took over ten years and a lot of stubborn refusal to use London time but, by 1855, almost all towns were using GMT (Greenwich Mean Time). In 1880, GMT became the legal time for the whole of Britain.
Other countries took up the system of railway time, but most of them are bigger countries than Britain. Charles F. Dowd realized that the same system it wouldn’t work in America without separate time zones. He suggested four time zones in 1870.
Scottish Canadian Sir Sandford Fleming took the idea to the next step and suggested worldwide time zones, in 1879. He suggested the day start at the Greenwich Meridian and increase in hourly increments. (Incidentally, Greenwich became the 0 meridian because at that time, Britain had more ships than all other countries in the world combined).
It took until 1929 before most countries were using the time zones based on GMT. The change was mostly brought about by the increase of international commercial flights. However, even today, some countries don’t use the time zone system. China should have 5 time zones, but the government has decided that the whole country will run on Beijing central time. That’s fine if you live in Beijing, but not so fine if you live on the western border and have to have lunch at 7am.
So, people had no need for standardized times and time zones before the invention of rail networks when timetabling made it necessary. It took the invention of the telegraph to make it possible to send the central time to far away cities, allowing for a standard time. And this is what I learned today.
Source
https://en.wikipedia.org/wiki/Time_zone
https://en.wikipedia.org/wiki/Railway_time
https://en.wikipedia.org/wiki/History_of_rail_transport#Britain