Before the late nineteenth century, there was no global standard time. There were only millions of local clock times ticking away without reference to one another. A railroad passenger traveling between Washington, DC and San Francisco in 1870 would have found it necessary to reset his watch more than two hundred times over the course of that journey.
Railroad travel itself helped create the need for time standardization in the second half of the nineteenth century. In 1883, the four time zones still in use in the continental United States today were agreed upon by the nation’s railway carriers.
The image below is an 1862 diagram of time zones around the world, with Washington, DC time in the center. This system left something to be desired, since Edinburgh was 12 minutes behind London.
Around this time, too, inventions like the telegraph first made it possible to think about standardizing time not only in one continent or region, but across the world. The first transatlantic telegraph cable had been laid in 1858, greatly facilitating intercontinental communications.
(By an extraordinary coincidence, two years later in 1860, scientists inside the first deep-sea submersible, a spherical contraption called the Bathysphere, discovered what they believed to be the world’s longest sea snake, until they realized it was the transatlantic telegraph cable lying on the ocean floor.)
In any event, new technologies like railroads and the telegraph highlighted the need for global time standardization. In 1884, representatives from twenty-five countries around the world gathered in Washington DC at the Prime Meridian Conference and proposed to make Greenwich, England the zero meridian. They also agreed to divide the earth into twenty-four time zones one hour apart, and they set a beginning for the world-wide day.
The rest of the world, however, was somewhat slow to adopt this system. Japan’s railroad network got on board four years later in 1888. Belgium and Holland followed in 1892, and several other European nations in 1893. But other countries continued to use their own systems. In Russia, St. Petersburg time was 2 hours, 1 minute, and 18.7 seconds ahead of Greenwich meridian time. In India, hundreds of local times were announced by gongs, guns, and bells.
But France was in total time chaos. Paris time was 9 minutes and 21 seconds ahead of Greenwich. Each French city had its own local time determined by the sun, and some French regions had four different time zones within them. An 1891 law made the railroads run according to Paris time, but to give passengers extra time to board, all trains ran five minutes behind schedule. As a result, the clocks inside train stations were five minutes ahead of those on the tracks. Finally, in 1911, French authorities decided that the legal time in France would be Paris time minus 9 minutes and 21 seconds—aligning France with the global time standard without admitting to having done so.
The International Conference on Time in 1912 finally resolved many of these problems and set a uniform system for determining and maintaining accurate time measurements around the world. Once this system was in place, local times gradually capitulated to the new global standard.