This map layer shows the 24 time zones commonly used in the Greenwich Mean Time model.
For example, China, a very large country, only uses one time zone while many places in the Middle East use half-hour time zones. However, at the conference, the committee decided that the world should identify an official meridian and they chose the Greenwich Meridian.Īlthough much has changed since the conference in 1884, Fleming’s design has stayed intact with variations based on political and geographic decisions. Previously, different countries had different prime meridians. Longitude lines mark the distance east or west of the prime meridian.įleming’s recommendations led to an international conference held in 1884 to select a common prime meridian, otherwise known as zero degrees longitude, on which to base time zones. He proposed to regulate time by dividing the earth into 24 one-hour time zones utilizing longitude lines, each 15 degrees apart. To prevent further damage, Canadian railway engineer Sir Sanford Fleming devised a globally standardized time system. Many towns used natural time markers so whenever they saw the sun highest in the sky, that was their “high noon.” This caused confusion and some collisions amongst trains as no one was following the same local time. Each town and city went by their own time which was usually regulated by a clock in the town center. Time standardization was greatly needed in a world becoming increasingly interconnected.įor example, in the United States, the railroad system faced big problems by the late 1800s. New technology and more accessible transportation, such as trains, allowed people, ideas, and goods to travel faster and more easily around the world. Explore the dataĬurious about America’s time zones? The National Transportation Atlas Database provides a digital representation of the geographic boundaries for the nine time zones that cover United States and its territories.In the late 19th century and into the early 20th century, the world globalized. National Council of State Legislatures map shows States with legislative activity to adopt year-round DST. Some States have enacted legislation to adopt DST as their permanent setting, pending federal approval. States can opt-out from DST, but such an exemption must apply to the entire portion of that State that lies in a given time zone (some states, like North Dakota, straddle two different zones). Currently, DST begins the second Sunday in March and ends the first Sunday in November. Congress has amended time change laws several times since then. The Standard Time Act of 1918, “an Act to save daylight and to provide standard time for the United States,” authorized the nation’s first “Daylight Saving Time” to begin on the last Sunday of March and conclude on the last Sunday of October. time zones as recorded in the National Transportation Atlas Database Daylight Saving Time rules begin in 1918 but have changed through the years Department of Transportation to change their time zone.Ĭurrent U.S. The early maps had today’s four time zones for the coterminous states, but the boundaries were very different from today. Time zone map of the United States from 1913, as published in the Chicago Daily News Almanac and Yearbook. British railroads were the first to adopt standard time in 1840, and railroads in the US and Canada adopted standard time zones in 1883. Thank the railroads for our standard time zonesīefore time zones were created, each locality set its own clocks to noon at the time of day when the sun was at its highest position. Virgin Islands) don’t practice the spring and autumn time change. territories (American Samoa, Guam, Northern Mariana Islands, Puerto Rico, and the U.S. Some states (Hawaii, Arizona-except for the Navajo Nation within the state) and U.S. Last weekend, millions of Americans turned back their clocks one hour to mark the return from Daylight Saving Time to Standard Time.
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