The Stupid History Of Daylight Saving Time The theory as to why we have DST goes back to something about saving energy. “Fast Time” as it was first introduced in the United States in 1918 was signed into law by President Woodrow Wilson in order to support World War I. 7 months later it was repealed by the majority of the states. Get our free mobile app President Franklin D. Roosevelt instituted year-round “War Time” in 1942. Once again the idea was to save energy. In 1966 Congress passed the Uniform Time Act establishing uniform times for starting and ending “War Time” or DST.