who came up with the idea of daylight saving time
Daylight saving time George Hudson proposed the idea of daylight saving in 1895.[4] The German Empire and Austria-Hungary organized the first nationwide implementation, starting on April 30, 1916. Many countries have used it at various times since then, particularly since the energy crisis of the 1970s.
Daylight saving time in the United States During World War I, in an effort to conserve fuel, Germany began observing DST on May 1, 1916. The rest of Europe soon followed. The plan was not adopted in the United States until the Standard Time Act of March 19, 1918, which confirmed the existing standard time zone system and set summer DST to begin on March 31, 1918 (reverting October 27).[4] The idea was unpopular and Congress abolished DST after the war, overriding President Woodrow Wilson's veto.[5] DST became a local option and was observed in some states until World War II, when President Franklin Roosevelt instituted year-round DST, called "War Time", on February 9, 1942.[6] It lasted until the last Sunday (the 30th) in September 1945. After 1945 many states and cities east of the Mississippi River (and mostly north of the Ohio and Potomac rivers) adopted summer DST.[7]