This article is part of the Energy.gov series highlighting the “Top Things You Didn’t Know About…” Be sure to check back for more entries soon.
8. This Sunday, people across the country will set their clocks forward an hour, marking the start to Daylight Saving Time. But it hasn’t always happened on the second Sunday in March. The Energy Policy Act of 2005, which was implemented in 2007, added four weeks to Daylight Saving Time by changing it to start on the second Sunday in March and end on the first Sunday in November.
7. Often mistakenly called daylight savings time, its official name in the U.S. is Daylight Saving Time. In European countries, it is called Summer Time.
6. Ever wonder why we change our clocks? While some think it is to give farmers an extra hour of sunlight in the evenings during warmer months, Daylight Saving Time was seen as a means to help reduce electricity use in buildings.
5. Sometimes credited with inventing Daylight Saving Time, Benjamin Franklin -- the man who is known for the saying “Early to bed and early to rise …” -- did not actually suggest a change in time. Franklin’s connection to Daylight Saving Time comes from his 1784 satirical letter to the editor in the Journal de Paris in which he proposed that Parisians could save money on candles by waking up before their normal time of noon.
4. Depending on how you phrase the question, Daylight Saving Time is either credited to a New Zealand entomologist who proposed the idea in a 1895 paper or an Englishman who campaigned to get the British parliament to pass a Daylight Saving Bill in 1908. In the end, Germany was the first country to implement Daylight Saving Time in 1916 to conserve resources during World War I.
3. The U.S. adopted Daylight Saving Time towards the end of World War I and then again during World War II, but between 1945 and 1966, there was no federal law regulating it. This led to confusion between states, and in 1966 Congress passed the Uniform Time Act to establish uniform dates for observing Daylight Saving Time.
2. Not all states will change their clocks on Sunday. Hawaii and Arizona (excluding the Navajo Nation) along with the U.S. overseas territories of American Samoa, Guam, Puerto Rico, the Virgin Islands and the Northern Mariana Islands do not observe Daylight Saving Time.
1. How much energy does Daylight Saving Time save? In 2008, Energy Department experts studied the impact of the extended Daylight Saving Time on energy consumption in the U.S. and found that the extra four weeks of Daylight Saving Time saved about 0.5 percent in total electricity per day. While this might not sound like a lot, it adds up to electricity savings of 1.3 billion kilowatt-hours -- or the amount of electricity used by more than 100,000 households for an entire year. These electricity savings generally occur during a three- to five-hour period in the evening. To learn how you can save energy during Daylight Saving Time, visit Energy Saver.