Standard Time Act

The Standard Time Act of 1918, also known as the Calder Act, was the first <a href="/facts/United_States/P0sCdLe5">United States</a> federal law implementing <a href="/facts/Standard_time/3dKMYnjM">Standard time</a> and <a href="/facts/Daylight_saving_time_in_the_United_States/BPWrSIYG">Daylight saving time in the United States</a>. It defined five time zones for the <a href="/facts/Continental_United_States/yx414G7a">continental United States</a> and authorized the <a href="/facts/Interstate_Commerce_Commission/Mg0bXMq7">Interstate Commerce Commission</a> 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The section concerning daylight saving time was repealed by the act titled An Act For the repeal of the daylight-saving law, <a href="/facts/Act_of_Congress/CE4cpsgt">Pub. L.</a> <a href="https://uslaw.link/citation/us-law/public/66/40">66–40</a>, 41 <a href="/facts/United_States_Statutes_at_Large/tT1dUjXo">Stat.</a> <a href="https://legislink.org/us/stat-41-280">280</a>, enacted August 20, 1919, over President <a href="/facts/Woodrow_Wilson/zE4yxK2X">Woodrow Wilson</a>'s veto.
As a result of a 1966 amendment of Section 261 to add more time zones, the wording in Section 264 of the act wrongly placed most of the state of <a href="/facts/Idaho/68ELs9Um">Idaho</a> (south of the <a href="/facts/Salmon_River_(Idaho)/luKkQtrn">Salmon River</a>) in <a href="/facts/UTC%25E2%2588%259206%3a00/h6pCEezn">UTC−06:00</a> CST (<a href="/facts/Central_Standard_Time/5UBgAgqS">Central Standard Time</a>), but was amended in 2007 by Congress to <a href="/facts/UTC%25E2%2588%259207%3a00/A2IfxDXM">UTC−07:00</a> MST (<a href="/facts/Mountain_Standard_Time/vA0CFQKG">Mountain Standard Time</a>). MST was observed prior to the correction.

Standard Time Act open-in-new

Standard Time Act