About the Arizona Time Zone
Prior to formation of time zones in the United States, time was more or less a local issue. In 1880 this all changed and standard time zones were established. In 1966, America's time was again to be effected with the birth of daylight saving time, which sets clocks an hour back during parts of the year to provide more daylight and to help reduce energy use. Although the use of Daylight Saving Time is a federal law, individual states actually have the power to choose whether or not they wish to observe the change.
Arizona is the only member of the continental United States that does not observe Daylight Saving Time. From November to March every year, Arizona finds itself in standard Mountain Zone time, but as Utah, Colorado, New Mexico, Wyoming, Idaho and Montana switch set their clocks an hour forward in March, Arizona does not partake. Instead, Arizona keeps the same time and as a result, aligns itself with Pacific Daylight Time held by its neighboring state, California. One may wonder why Arizona has taken exception to a practiced followed by the rest of the country. Arizona's motivation for not observing Daylight Saving Time comes largely from the state's unusually warm climate. In the summer months, Arizona experiences temperatures that are consistently in triple digits. This hot weather makes the night hours more appealing to residents for activities and social gatherings. For this reason, while the rest of the country is attracted to the idea of more daylight, the Arizona heat makes more daylight highly undesirable. In fact, Arizonians highly detested the implementation of Daylight Saving Time in their state and devoted a great deal of effort into creation petitions against the law. In the end, Arizona was victorious and President Nixon allowed Arizona to be exempt from the daylight saving law.
To make the issue of Arizona's time zone more interesting, there is a small portion of the state that does observe Daylight Saving Time. The state's Navajo Indian Reservation does follow standard Daylight Saving Time procedures and follows the lead of other Mountain Zone states year around. The Navajo reservation chooses not to follow Arizona's time choice, because their reservation extends across three additional states (New Mexico, Colorado and Utah), which all follow Daylight Saving Time. This unique case creates a situation where a seventh of Arizona is an hour ahead of the rest of the state from March to November each year.
Arizona can boast of being a state that exists in two time zones. During standard time, Arizona's clock is synchronized with its Mountain Time Zone counterparts, but during Daylight Saving Time, the state's clock resembles its Pacific neighbors. All the while, the Navajo Indian Reservation has a different time from the rest of the state for half the year. Arizona's time zone situation may be the most interesting in the entire United States, but there are other states/U.S. territories that don't follow the rules; Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands all choose not to observe Daylight Saving Time.