Daylight Saving Time - Birth of a Burden
In 1918, in order to conserve resources for the war effort, Congress placed the country on Daylight Saving Time for the remainder of WW I. It was observed for seven months in 1918 and 1919. The law, however, proved so unpopular that the law was later repealed.
When the country went to war again, Congress reinstated Daylight Saving Time on February 2, 1942. Time in the U.S. was advanced one hour to save energy. From 1945 to 1966, there was no federal law about Daylight Saving Time. So, states and localities were free to observe Daylight Saving Time or not. By 1966, some 100 million Americans were observing Daylight Saving Time through their own local laws and customs. Congress decided to step in and end the confusion and establish one pattern across the country. The Uniform Time Act of 1966 (15 U.S. Code Section 260a) created Daylight Saving Time to begin on the last Sunday of April and to end on the last Sunday of October. Any area that wanted to be exempt from Daylight Saving Time could do so by passing a local ordinance. The law was amended in 1986 to begin Daylight Saving Time on the first Sunday in April. Read more on the NIST site.