Skip to Main Content

This Month in Business History

The Day of Two Noons

Rand McNally and Company. Burlington Route. 1865. Library of Congress Geography & Map Division.

Railroads in the 19th century ran their trains set on their own clocks, which meant different companies ran their trains on different times. This difference could lead to wrecks and many deaths but, on November 18, 1883, individual railroad station clocks were reset as standard-time noon was reached within each time zone—hence the Day of Two Noons—making the movement of people and goods in the United States safer.

The 19th century was a time of great change. The railroads were born and they grew to play a major role in the movement of people and goods throughout the country.

At the same time, the use of well-regulated mechanical clocks became more common. These clocks allowed places to set a better local mean solar time and in turn, meant railroad companies used that time to run trains throughout their system. Since solar mean time can differ from place to place depending on its geographical longitude, time could be different depending on where it was measured and by whom. Because there could be different times for different companies, the confusion became more dangerous as the number of train routes and the use of them for travel and trade, increased. The desire for a more standardized time became more urgent.

Charles F. Dowd made the first proposal for a one-hour standard time zone for American railroads in 1863, but his system was never accepted. The railroads instead implemented a version proposed by William F. Allen, the editor of the Traveler's Official Railway Guide whose system had five time zones named Intercolonial, Eastern, Central, Mountain, and Pacific. On November 18, 1883 every railroad clock was reset—even those that had had already passed noon—hence the Day of Two Noons.

However, the history of standardized time measurement and time zones was to be revisited. On March 19, 1918 the first federal law implementing Standard time—Standard Time Act of 1918—was passed and also included the creation of Daylight Saving Time in the United States. Over time however, many states used daylight saving differently, once again creating a confusing situation. The Uniform Time Act of 1966 (Pub.L. 89–387, 80 Stat. 107) was enacted on April 13, and was designed to "promote the adoption and observance of uniform time within the standard time zones". The subject was revisited again to correct Section 264 of the 1918 act, by moving all of Idaho into the Mountain Standard Time.

Standardized time measurement is an international concern. Other countries have the same internal needs and it is an important aspect of efficient international trade and communication. In 1960, the U.S. and UK used "Coordinated Universal Time" and by the next year, the Bureau International de l'Heure (International Time Bureau) began coordinating the UTC process internationally, though adoption was not as abrupt as it was in November 1883. There was a Uniform Time Conference in 1962, and on August 13, 1962, the Committee for Time Uniformity was formed at the behest of the Transportation Association of America. The next year UTC was adopted internationally, though the official abbreviation of UTC and its French equivalent were not adopted until 1967.

If you have any further questions, please Ask A Librarian.

Print Resources

The following titles link to fuller bibliographic information in the Library of Congress Online Catalog. Links to digital content are provided when available.

Library of Congress Digital Resources

The following resources have been created and digitized by the Library of Congress that can be used to find resources of people traveling across the United States as well as the events of the day.

Internet Resources

These freely available online resources provide additional information on the topic.

LC Catalog Searches

Additional works on this topic in the Library of Congress may be identified by searching the Library of Congress Online Catalog under appropriate Library of Congress subject headings. Choose the topics you wish to search from the following list of subject headings to link directly to the Catalog and automatically execute a search for the subject selected. Please be aware that during periods of heavy use you may encounter delays in accessing the catalog. For assistance in locating other subject headings that may relate to this subject, please consult a reference librarian.