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 primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
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 r ...
and
Daylight saving time in the United States
The majority of the United States observes daylight saving time, the practice of setting the clock forward by one hour when there is longer daylight during the day, so that evenings have more daylight and mornings have less. Exceptions include ...
.
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 eliminat ...
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The section concerning daylight saving time was repealed by the act titled ''An Act For the repeal of the daylight-saving law'', , over President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 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 Montana and Wyom ...
(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 Coordinate ...
), 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 clo ...
).
MST was observed prior to the correction.
See also
*
Time in the United States
Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to c ...
*
Uniform Time Act
The Uniform Time Act of 1966, , was a Law of the United States to "promote the adoption and observance of uniform time within the standard time zones" prescribed by the Standard Time Act of 1918. Its intended effect was to simplify the official ...
References
Time in the United States
Daylight saving time in the United States
65th United States Congress
1918 in law
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