From this Sunday clocks back one hour in much of USA

NEW YORK In much of the territory of the United States will be delayed one hour to watches, from this Sunday first, to become the official time, not going well in the states of Arizona, Hawaii, Samoa, Guam , Puerto Rico and the Virgin Islands.

As every autumn, the days begin to make shorter, interfering with the routine of many Americans. This measure, adopted in the US since 1918, is to save energy throughout the country, as do many countries in Europe since World War II in order to increase the maximum energy saving and better use of sunlight shining during daytime hours.

After the end of World War II the unpopularity of the move prompted the US Congress repudiated the schedule change with a sufficient majority to override the veto of President Woodrow Wilson, but President Franklin D. Roosevelt reinstated the schedule change during World War II (1939-1945), from February 1942 to September 1945.

In 1974 President Richard Nixon after the crisis by the Arab oil embargo he enacted a federal law that implemented the schedule change, which continued to apply irregularly until 1986 another federal law provided the mechanism for most of the country.

In 2005, then-President George W. Bush signed an Energy Policy Act which stipulated that the winter schedule would begin from 2007, the first Sunday in November, and not the last October, as had been before. The change was due to the "Energy Policy Act" that reset the days of the winter and summer.

Because this legislation passed in 2005, DST (or as it is known in English, Daylight Saving Time) in the United States begins the second Sunday in March and ends on the first Sunday in November.

The Department of Transportation is responsible for overseeing the time change dates from 1966, when Congress transferred this responsibility until then of the Interstate Commerce Commission. He will make the change to the schedule in March 2016.