Arizona Daylight Savings Time traffic sign

Time in Arizona, as in all U.S. states, is regulated by the

United States Department of Transportation The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the president of the United States a ...

as well as by state and tribal law. All of

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

is in the

Mountain Time Zone The Mountain Time Zone of North America keeps time by subtracting seven hours from Coordinated Universal Time (UTC) when standard time ( UTC−07:00) is in effect, and by subtracting six hours during daylight saving time ( UTC−06:00). The ...

. Since 1968, most of the state—except the

Navajo Nation The Navajo Nation (), also known as Navajoland, is an Indian reservation of Navajo people in the United States. It occupies portions of northeastern Arizona, northwestern New Mexico, and southeastern Utah. The seat of government is located in ...

—does not observe

daylight saving time Daylight saving time (DST), also referred to as daylight savings time, daylight time (Daylight saving time in the United States, United States and Daylight saving time in Canada, Canada), or summer time (British Summer Time, United Kingdom, ...

and remains on Mountain Standard Time (MST) all year. This results in most of Arizona having the same time as neighboring California each year from March to November, when locations in the

Pacific Time Zone The Pacific Time Zone (PT) is a time zone encompassing parts of western Canada, the western United States, and western Mexico. Places in this zone observe standard time by subtracting eight hours from Coordinated Universal Time ( UTC−08:00 ...

observe daylight saving time.

Daylight saving time

Unlike most of the United States, Arizona does not observe

(DST), with the exception of the

, which does observe DST. The Hopi Reservation, which is not part of the Navajo Nation but is geographically surrounded by it, also does not observe DST. For this reason, driving the length of Arizona State Route 264 east from Tuba City while DST is in place involves six time zone changes in less than .

Reasoning

Because of Arizona's hot climate, DST is largely considered counterproductive. The argument against extending the daylight hours into the evening is that people prefer to do their activities in the cooler morning temperatures. The Navajo Nation, a semi-autonomous Native American territory, follows the United States DST schedule. It lies in northeastern Arizona, northwestern New Mexico, and southeastern Utah and thus maintains the same time throughout tribal lands despite state borders.

Legislative history

On March 21, 1968, the Arizona legislature passed the final version of SB 1, placing Arizona under standard time. The bill had been working its way through the legislature since January of that year, and was sponsored by state Senators Tenney, Goetze, Porter, Halacy, Garfield, Campbell, Lewis, Gregovich, Giss, Crowley, and Holsclaw. It passed the Senate 25–3–2, and afterwards the bill was passed by the House 49–1–10. It was approved by Governor Jack Williams the same day.

tz database

The tz database version contains two entries for Arizona:

Example

When daylight saving is not active, the time in Phoenix and

Albuquerque, New Mexico Albuquerque ( ; ), also known as ABQ, Burque, the Duke City, and in the past 'the Q', is the List of municipalities in New Mexico, most populous city in the U.S. state of New Mexico, and the county seat of Bernalillo County, New Mexico, Bernal ...

, is the same (Mountain Standard Time), and both are one hour ahead of

Los Angeles, California Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

(Pacific Standard Time). When daylight saving is active, the time in Phoenix (Mountain Standard Time) and Los Angeles (Pacific Daylight Time) is the same, and both are one hour behind Albuquerque (Mountain Daylight Time). The time on the Navajo Nation is always the same as in Albuquerque.

References

{{Time in the United States

Geography of Arizona