<P> Use of standard time gradually increased because of its obvious practical advantages for communication and travel . Standard time in time zones was not established in U.S. law until the Standard Time Act of 1918 of March 19 , 1918 , also known as the Calder Act ( 15 USC 260 ) . The act also established daylight saving time , itself a contentious idea . </P>
<P> Use of standard time gradually increased because of its obvious practical advantages for communication and travel . Standard time in time zones was not established in U.S. law until the Standard Time Act of 1918 of March 19 , 1918 , also known as the Calder Act ( 15 USC 260 ) . The act also established daylight saving time , itself a contentious idea . </P>
when did we start using daylight savings time in the united states
when did we start using daylight savings time in the united states
1918
1918