Building the World

TRANSPORT: Day of Two Noons


18 November – Day of Two Noons.

Image: Anakin101. Donated to public domain, wikimedia. Included with appreciation

Transport has advanced civilization in many ways, but did you know that trains gave us standard time zones? When railroads began to connect the world, there were no established time zones. Each city had a town clock, sometimes a sun dial: when the device displayed “noon,” all the businesses and homes in that city would set their own clocks accordingly. As a result, noon was slightly different in Albany and in New York City: this was acceptable for cities but not for the trains that connected them. Accidents plagued the new mode of transport, and became a serious hazard with the building of the Transcontinental Railroad, approved in 1862 and completed in 1869.

“East and West Shaking Hands,” photograph of the completion of the Transcontinental Railroad by Andrew J. Russell, public domain. Included with appreciation.

It was railroad engineers who introduced the idea of standard time zones. In the United States, Charles F. Dowd proposed the concept in 1863, but it would be twenty years until a five-zone system designed by William F. Allen, editor of a railway guide, became law. On 18 November, 1883, at noon, every railroad clock was reset. Some towns and stations had already passed noon on their sundial, so November 18, in 1883, became known as the Day of Two Noons.

“TIme Zones (2012)” showing the zones in reference to the Prime Meridian or Greenwich Meridian. Image by NASA. Public domain. Included with appreciation.

International time zones soon followed. Sandford Fleming, surveyor on the Canadian Pacific Railway, proposed standardizing time zones across the world. In 1884, the International Prime Meridian Conference, meeting in Washington, DC and chaired by Count Lewenhaupt, Delegate for Sweden, adopted the system of AM and PM (Ante Meridiem and Post Meridiem) based on Greenwich Mean Time and coordinated globally, on 22 October 1884.

Today, 18 November, when your time-keeping device (be it digital, analogue, or solar – phone, clock, or sundial), take a minute to celebrate the Day of Two Noons.

Davidson, Frank P and K. Lusk Brooke,  “The Transcontinental Railroad,” pages 205 – 218; “The Canadian Pacific Railway,” pages 253-287. Building the World. Westport: Greenwood, 2006.

International Prime Meridian Conference.

New York Times. “Turning Back the Hands: A Quiet Change to the Standard Time.” 18 November 1883. Digital reproduction of text:

Terrell, Ellen. “The Day of Two Noons.” January 2021. Library of Congress.

Building the World Blog by Kathleen Lusk Brooke and Zoe G. Quinn is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Un

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