The Standard Time Act of 1918, also known as the Calder Act, was the first

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

federal law implementing

Standard time Standard time is the synchronisation of clocks within a geographical region to a single time standard, rather than a local mean time standard. Generally, standard time agrees with the local mean time at some meridian that passes through the ...

and Daylight saving time in the United States. It defined five time zones for the United States and authorized the

Interstate Commerce Commission The Interstate Commerce Commission (ICC) was a regulatory agency in the United States created by the Interstate Commerce Act of 1887. The agency's original purpose was to regulate railroads (and later trucking) to ensure fair rates, to elimina ...

to define the limits of each time zone. The section concerning daylight saving time was repealed by the act titled ''An Act For the repeal of the daylight-saving law'', , over President

Woodrow Wilson Thomas Woodrow Wilson (December 28, 1856February 3, 1924) was an American politician and academic who served as the 28th president of the United States from 1913 to 1921. A member of the Democratic Party, Wilson served as the president of ...

's veto. Section 264 of the act mistakenly placed most of the state of

Idaho Idaho ( ) is a U.S. state, state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Monta ...

(south of the Salmon River) in UTC−06:00 CST (

Central Standard Time The North American Central Time Zone (CT) is a time zone in parts of Canada, the United States, Mexico, Central America, some Caribbean Islands, and part of the Eastern Pacific Ocean. Central Standard Time (CST) is six hours behind Coordina ...

), but was amended in 2007 by Congress to UTC−07:00 MST (

Mountain Standard Time The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC) when standard time ( UTC−07:00) is in effect, and by subtracting six hours during daylight saving time ( UTC−06:00). The cloc ...

). MST was observed prior to the correction.

References

Time in the United States Daylight saving time in the United States 65th United States Congress 1918 in law {{US-law-stub

See also

References