Why Do We Have Time Zones? || The Past That Shaped Us

Why do we have Time Zones? || Kudos365 History Series 

How the railroad transformed something as natural as noon into a worldwide system

For most of human history, time was local. Noon arrived when the sun reached its highest point in the sky. A town set its clocks accordingly, and another town some distance away did the same. Because longitude affects when the sun reaches its highest point, neighboring communities could have slightly different times.
For centuries, that hardly mattered. Most people traveled slowly, communication over long distances took time, and there was little reason for clocks hundreds of miles apart to agree. Then the railroad changed the equation.

When Local Time Became a Problem

By the nineteenth century, railroads were carrying people and goods rapidly between communities that kept different local times. In North America, railroads eventually had to contend with dozens of different railway and local time standards.
A passenger trying to read a timetable could encounter one time in the city of departure, another at the destination, and perhaps still another being used by the railroad itself.
What had once been harmless local variation had become an obstacle to operating an interconnected society. The solution was deceptively simple: instead of changing the clock continuously as one traveled east or west, large geographic areas would agree to use the same time. The modern time zone was emerging.

The Day the Clocks Changed

Railroad officials in the United States and Canada took the decisive step. William F. Allen, an editor of a prominent railway guide, helped develop a standardized system for the North American railroads. On November 18, 1883, most U.S. and Canadian railroads adopted Standard Railway Time, replacing a confusing collection of local and railroad times with a small number of standardized zones.
The adjustment produced an unusual experience in some communities. Clocks reached local noon and were then reset to reach noon again under the new standard. The occasion became known as the “Day of Two Noons.” 
The railroads had no authority to order every American to change a clock. But their network was becoming so important to commerce and everyday life that communities increasingly adopted railroad time themselves. Technology had effectively created a new social standard before government formally established one.

Turning a Railroad Solution into a World System

The problem extended well beyond North America. As steamships, telegraphs, international commerce and increasingly precise navigation connected distant parts of the world, countries also needed a common geographic reference for longitude and time.
One influential advocate was Canadian railway engineer Sandford Fleming, who promoted a worldwide system divided into 24 zones. Fleming was neither the first nor the only person to propose standardized world time, but he became an important advocate for international reform. 
In 1884, representatives gathered in Washington, D.C., for the International Meridian Conference. They recommended establishing the meridian through Greenwich, England, as the world's prime meridian and using it as the common starting point for longitude and universal time. Countries gradually developed their own standardized systems around this framework.
In the United States, Congress did not formally establish standard time in federal law until the Standard Time Act of 1918, decades after the railroads had introduced their system. 

The Map Is Not as Neat as the Idea

In theory, dividing a 24-hour day around the 360 degrees of the Earth suggests 24 zones averaging 15 degrees of longitude each.
Look at an actual time-zone map, however, and the boundaries zigzag. That is because people don't live according to longitude alone. Countries and communities have adjusted their time zones to accommodate borders, commerce, transportation and political preferences. Some nations span several zones; others have chosen one time for the entire country. Some regions use offsets of a half-hour or even 45 minutes rather than a full hour. The result is a fascinating compromise between astronomical time and human convenience. (NIST)

The World the Time Zone Created

The importance of standardized time extends far beyond knowing when to change a watch while traveling. Modern aviation depends upon coordinated time. So do global financial markets, telecommunications, shipping, broadcasting, scientific observation and computer networks. A video conference can bring together people on several continents because everyone can translate a scheduled moment into local time. Even our everyday expectation that clocks should agree is historically unusual.
Before standardized time, the clock largely described where you were. Today, it helps coordinate where everyone else is.

Historical Significance

Time zones are a small but revealing example of something that happened repeatedly as the modern world developed. New technologies connected communities that had once functioned largely independently. Those connections then required common standards—of time, measurement, communication and countless other things.
The railroad didn't invent time. It created a world in which local time was no longer enough. And from that practical nineteenth-century problem emerged an invisible system that now helps billions of people coordinate their lives every day.
That is one of the quiet ways the past still shapes us.

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