saving

Currently, Arizona, Hawaii, the eastern time zone portion of Indiana, Puerto Rico, the U.S. Virgin Islands and American Samoa do not observe Daylight Saving Time.

Source: World Almanac and Book of Facts 2005, p. 387.  California Energy Commission web site.
 

Per the Energy Policy Act of 2005, Daylight Saving Time was extended to begin the second Sunday in March and end the first Sunday of November. This change went into effect in 2007.

2013, Begins 10 March, Ends 3 November
2014, Begins 9 March, Ends 2 November
2015, Begins 8 March, End 1 November

History of daylight savings time provided by U.S. Naval Observatory .

Source: Chase's Calendar of Events, 2013, pp. 614-616.
 

Benjamin Franklin suggested people set their clocks ahead in the summer as far back as 1784. The first systematic use of Daylight Saving Time did not occur until the Germans began setting clocks ahead in World War I to conserve fuel. Soon, Britian and other Western European countries had also adopted "Summer Time."
The U.S. observed this time change nationwide in 1918 and 1919 and again in World War II from February 9, 1942, through September 30, 1945.