Benjamin Franklin is credited with the concept of Daylight Saving Time. The basic idea is to make the best use of daylight hours by shifting the clock forward in the Spring and backward in the Fall. Daylight Saving Time has been in use throughout much of the United States, Canada and Europe since World War I. In 1966, President Lyndon Johnson signed an act into law whereby Daylight Saving Time begins on the last Sunday of April and ends on the last Sunday of October each year. However, any State can opt out of Daylight Saving Time by passing a State law.
Hawaii does not observe Daylight Saving Time and neither does Arizona (although the Navajo Nation, in northeastern Arizona, does). For many years, most of Indiana did not observe Daylight Saving Time with the exception of 10 counties. Beginning in 2006, all of Indiana now observes Daylight Saving Time. However, the state remains divided in two time zones. Seventy-four counties (including state capital Indianapolis) are in the Eastern Time Zone. The 18 remaining counties are in the Central Time Zone (see: Indiana Time Zones).
US Federal law was amended in 1986 to begin Daylight Saving Time on the first Sunday in April:
Daylight Saving Time begins at 2 a.m. on the first Sunday of April
Daylight Saving Time ends at 2 a.m. on the last Sunday of October
In 2005, President Bush signed into law a new energy policy bill that would extend Daylight Saving Time by 4 weeks beginning in 2007:
Beginning in 2007:
Daylight Saving Time begins at 2 a.m. on the second Sunday of March
Daylight Saving Time ends at 2 a.m. on the first Sunday of November
The corresponding time zones in Canada also switch to Daylight Saving Time on the same dates. However, some regions of in British Columbia and Saskatchewan do not use Daylight Saving Time. They include: Charlie Lake, Creston (East Kootenays), Dawson Creek, Fort St. John, and Taylor (all in British Columbia), and most of Saskatchewan (except Creighton and Denare Beach).
In Europe, Daylight Saving Time is referred to as Summer Time. Throughout most of western Europe (including members of the European Community (EC)):
Summer Time (Daylight Saving) Begins at 1 a.m. GMT on the last Sunday of March
Summer Time (Daylight Saving) Ends at 1 a.m. GMT on the last Sunday of October
The following table gives the dates and times when Daylight Saving Time is in effect in the United States and Europe from 2001 through 2015:
| Daylight Saving Time 2001 - 2015 | ||||
| Year | United States | European Union | ||
| | Daylight Saving Time Begins at 2 a.m. | Daylight Saving Time Ends at 2 a.m. | Summer Time Begins at 1 a.m. GMT | Summer Time Ends at 1 a.m. GMT |
| 2001 | April 01 | October 28 | March 25 | October 28 |
| 2002 | April 07 | October 27 | March 31 | October 27 |
| 2003 | April 06 | October 26 | March 30 | October 26 |
| 2004 | April 04 | October 31 | March 28 | October 31 |
| 2005 | April 03 | October 30 | March 27 | October 30 |
| 2006 | April 02 | October 29 | March 26 | October 29 |
| 2007 | March 11 | November 04 | March 25 | October 28 |
| 2008 | March 09 | November 02 | March 30 | October 26 |
| 2009 | March 08 | November 01 | March 29 | October 25 |
| 2010 | March 14 | November 07 | March 28 | October 31 |
| 2011 | March 13 | November 06 | March 27 | October 30 |
| 2012 | March 11 | November 04 | March 25 | October 28 |
| 2013 | March 10 | November 03 | March 31 | October 27 |
| 2014 | March 09 | November 02 | March 30 | October 26 |
| 2015 | March 08 | November 01 | March 29 | October 25 |
