How did time zones come about?

Time zones were created because railways made local sun-based time unworkable. North American railroads put standard zones into effect on November 18, 1883, and in 1884 an international conference in Washington chose Greenwich as the prime meridian and recommended dividing the globe into twenty-four one-hour zones. Other nations adopted the system gradually. [1] [2]

For centuries, towns set their clocks by the position of the sun, so noon fell at a slightly different moment in each place. According to the Smithsonian, there were hundreds of local times in the United States before 1883. The BBC puts the figure at no fewer than 144 time zones in North America. Because most people did not travel far, this rarely mattered until trains arrived. [1] [3]

Railroads then faced scheduling trouble. Jon Goldman of the B&O Railroad Museum says that at best people missed trains and at worst trains on single track were more likely to collide. In the 1850s American railroads ran on about fifty regional times of their own. Britain had faced the same issue earlier: by 1847 all British railway companies had adopted a single Railway Time, which became Greenwich Mean Time and was adopted nationwide in 1880. [3] [1]

In 1881, fearing government intervention, railroad managers asked publisher William Frederick Allen to devise a simpler plan. He proposed zones based on a central meridian each, fifteen degrees of longitude, or one hour, apart, and campaigned for support. Standard Railway Time began at noon on November 18, 1883. The four zones adopted were Eastern, Central, Mountain and Pacific. Many people briefly lived with two noons, and some resented the loss of local autonomy. [1] [2]

The Library of Congress notes that the push for standard time did not start with the railroads. Astronomers and geophysicists wanted simultaneous observations from scattered places, and Cleveland Abbe lobbied for a uniform time from 1875. His committee's 1879 report helped persuade the railroads' General Time Convention. The US government did not formally take over civil time until 1918. [2] [3]

Sandford Fleming, a Canadian Pacific Railroad engineer, is widely credited with the worldwide scheme. The Smithsonian says he was first to publish a plan for twenty-four lettered zones, in 1876. The BBC dates his idea to 1879 and ties it to missing a train. The sources therefore differ on dates and emphasis, and Allen and Abbe also shaped the North American system. [1] [3] [2]

The 1884 International Meridian Conference chose the Greenwich meridian as the common zero of longitude, since longitude has no natural starting point and Greenwich was already widely used by mariners and mapmakers. Delegates recommended twenty-four zones one hour apart, and nations adopted them gradually. [2] [1] [4]