<P> The U.S. federal Uniform Time Act became law on April 13 , 1966 and it mandated that DST begin nationwide on the last Sunday in April and end on the last Sunday in October , effective in 1967 . The act explicitly preempted all previously enacted state laws related to the beginning and ending of DST effective in 1966 . Any state that wanted to be exempt from DST could do so by passing a state law , provided that it exempted the entire state , and Alaska , Arizona , Hawaii , Indiana , and Michigan chose to do so . However , Alaska , Indiana , and Michigan subsequently chose to observe DST . The law was amended in 1972 to permit states that straddle a time zone boundary to exempt the entire area of the state lying in one time zone . Indiana chose to exempt the portion of the state lying in the Eastern Time Zone ; however , that exemption was eliminated in 2006 and the entire state of Indiana now observes DST , leaving Arizona ( with the exception of the Navajo Nation ) and Hawaii as the only two states not to observe DST . On July 8 , 1986 , President Ronald Reagan signed the Federal Fire Prevention and Control Act of 1986 into law that contained a daylight saving rider authored by Senator Slade Gorton ( R - WA ) . The starting date of DST was amended to the first Sunday in April effective in 1987 . DST continued to end on the last Sunday in October . While the states retain the capability to exempt themselves from DST , they are forbidden by the 1966 federal law ( 15 USC 260a ( b ) ) from increasing a state 's time spent on DST , unless the United States Congress does this for the entire nation . </P>
<P> The U.S. federal Uniform Time Act became law on April 13 , 1966 and it mandated that DST begin nationwide on the last Sunday in April and end on the last Sunday in October , effective in 1967 . The act explicitly preempted all previously enacted state laws related to the beginning and ending of DST effective in 1966 . Any state that wanted to be exempt from DST could do so by passing a state law , provided that it exempted the entire state , and Alaska , Arizona , Hawaii , Indiana , and Michigan chose to do so . However , Alaska , Indiana , and Michigan subsequently chose to observe DST . The law was amended in 1972 to permit states that straddle a time zone boundary to exempt the entire area of the state lying in one time zone . Indiana chose to exempt the portion of the state lying in the Eastern Time Zone ; however , that exemption was eliminated in 2006 and the entire state of Indiana now observes DST , leaving Arizona ( with the exception of the Navajo Nation ) and Hawaii as the only two states not to observe DST . On July 8 , 1986 , President Ronald Reagan signed the Federal Fire Prevention and Control Act of 1986 into law that contained a daylight saving rider authored by Senator Slade Gorton ( R - WA ) . The starting date of DST was amended to the first Sunday in April effective in 1987 . DST continued to end on the last Sunday in October . While the states retain the capability to exempt themselves from DST , they are forbidden by the 1966 federal law ( 15 USC 260a ( b ) ) from increasing a state 's time spent on DST , unless the United States Congress does this for the entire nation . </P>
when did daylight saving time begin in the united states
when did daylight saving time begin in the united states
1967
1967