Daylight Savings Time in the United States begins each year on the 2nd Sunday in March, when clocks are set forward by 1 hour. They are turned back again to standard time on the 1st Sunday in November as DST ends.
Daylight Savings Time in the United States is synchronized. By law, all areas taking part in the DST switch must do so on the same dates and at the same local time. All clock changes occur at 02:00 (2 am). In the spring, clocks are set forward to 03:00 (3 am); in the fall, they are turned backward to 01:00 (1 am). However, since the United States spans several time zones, the clock changes, while occurring at the same local time in each time zone, do not happen simultaneously. Eastern time zones switch earlier than western time zones. For example, each DST change happens 3 hours earlier in New York than in Los Angeles.
In 1916, during World War I, Germany became the first country to adopt DST to save energy for the war effort. Many countries across Europe soon followed suit. In the US, “Fast Time”, as it was called then, was first introduced in 1918. The initiative was sparked by Robert Garland, a Pittsburgh industrialist who had encountered the idea in the United Kingdom.
In 1942, at the height of World War II, President Franklin D. Roosevelt reintroduced the measure, instituting year-round Daylight Savings Time in the United States. Referred to as “War Time”, DST was in force continuously from February 9, 1942, to September 30, 1945. During this time, the US time zones were called “Eastern War Time”, “Mountain War Time”, “Central War Time”, and “Pacific War Time”. After the surrender of Japan in mid-August 1945, the time zones were relabeled “Peace Time”.
From 1945 to 1966, there were no uniform rules for DST in the US. This caused widespread confusion, especially for trains, buses, and the broadcasting industry. As a result, the Uniform Time Act of 1966 was established. While granting US states the ability to opt out of DST, the law provided a framework for a nation-wide, synchronized DST schedule, starting on the last Sunday of April and ending on the last Sunday of October.
After the energy crisis was over in 1976, the DST schedule in the US was revised several times throughout the years. From 1987 to 2006, the country observed DST for about 7 months each year. The current schedule was introduced by the Energy Policy Act of 2005 and has been followed since 2007.