Which states do not observe Daylight Saving Time?

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.  None of the US dependencies observe DST. This includes American Samoa, Guam, Puerto Rico, Northern Mariana Islands, the US Minor Outlying Islands, and the US Virgin Islands. 


When does Daylight Saving Time begin and end?

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.

2017 - DST begins March 12, ends November 5
2018 - DST begins March 11, ends November 4
2019 - DST begins March 10, ends November 3
2020 - DST begins March 8, ends November 1

For more information see the U.S. Naval Observatory site.

What is the history of Daylight Saving Time in Tulsa?

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.