03/10/2026
HISTORY OF STANDARD TIME IN THE UNITED STATES
(Summarized by Bob Thatcher from āThe Day of Two Noonsā as published by the Association of American Railroads)
What we now know as āStandard Timeā did not exist in the United States prior to the late 19th Century. Historically, each local town established as a standard Noon when the sun appeared at the highest point in the sky over city hall or other designated location (āsun timeā). However, due to varying global longitudes, at a given moment there would be many sun times among towns from east to west. For instance, at 12:00 Noon in Washington DC the local sun times would be 12:12 PM (New York City), 11:36 AM (Detroit MI) and 11:18 AM (Chicago IL).
Much as Artificial Intelligence usage is rapidly expanding in the 21st Century, the railroad network in the United States rapidly expanded in the 19th Century, especially after the Civil War. In order to minimize chaos and accidents, individual railroads established official times for their operations, often using the sun time at the headquarters city. While this helped smooth operations on a given railroad, passengers and others replying upon departure and arrival times were confronted a confusing variety of āstandardā times.
To rectify this situation, the railroad industry established the four Standard Time zones with which we are familiar today (Eastern, Central, Mountain and Pacific) effective November 18, 1883. Eventually, the Federal Government adopted responsibility for maintaining Standard Time and the time zone boundaries. So, āWhat Time Is It?" can be accurately answered today due to the efforts of the railroad industry some 140 years ago.
