Today in History: Keeping Time

Standard time zones of the world 2011
Today in History–November 18–the Library of Congress features time. On this day in 1883, precisely at noon, North American railroads switched to Standard Railway Time (SRT). SRT was quickly adopted throughout the United States, resulting in the creation of four national time zones: eastern, central, mountain and Pacific. A year later, at an international conference in Washington D.C., the meridian passing through Greenwich was adopted as the initial or prime meridian for longitude and timekeeping, creating 24 time zones 15 degrees wide, on average. Individual time zone boundaries are not straight, however, because local populations have adjusted them to suit their needs. Learn more about time zones and time keeping by visiting the Today in History section, then click the links below to access more related resources.

Historic newspaper articles: Standard Railway Time

19th-century periodical articles

Standard time legislation

Whose Time is it Anyway? A Brief History of Standardized Time Zones in the United States In Custodia Legis

Four Standard Time Zones for the Continental U.S. Were Introduced from America’s Library

Daylight Savings Time

Time Zones

More time resources