Daylight Saving Time in The United States - 2005 Revision To Dates of Observance

2005 Revision To Dates of Observance

By the Energy Policy Act of 2005, daylight saving time (DST) was extended in the United States beginning in 2007. As of that year, DST began on the second Sunday of March and ended on the first Sunday of November. These changes result in a DST period that is four weeks longer than in previous years. In 2008 daylight saving time ended at 2:00 a.m. (0200) on Sunday, November 2, and in 2009 it began at 2:00 a.m. on Sunday, March 8. Wyoming Senator Michael Enzi and Michigan Representative Fred Upton advocated the extension from October into November especially to allow children to go trick-or-treating in more daylight.

The date and time of all clock changes is determined by the week number in March or November, but always happens at 2:00 a.m. on a Sunday. Clocks "Spring" forward in the second week of March, and "Fall" back in first week of November. The following table lists the dates of DST under the current law through 2025:

Under Section 110 of the Act, the U.S. Department of Energy was required to study the impact of the 2007 DST extension no later than nine months after the change took effect. The report, released in October 2008, reported a nationwide electricity savings of 0.03% for the year of 2007.

An October 2008 study conducted by the University of California at Santa Barbara for the National Bureau of Economic Research found that the 2006 DST adoption in Indiana increased energy consumption in Indiana by an average of 1%. Although energy consumption for lighting dropped as a result of the DST adoption, consumption for heating and cooling increased by 2 to 4%. The cost to the average Indiana household of the DST adoption was determined to be $3.29 per year, for an aggregate cost of $1.7 million to $5.5 million per year.