Time in Arizona


Time in Arizona, as in all U.S. states, is regulated by the United States Department of Transportation.
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.
Arizona is in the Mountain Time Zone and most of the state remains in Mountain Standard Time all year. Thus, during daylight saving time, from March to November, most of Arizona has the same time as the Pacific Time Zone.

Daylight saving time

Unlike most of the United States, Arizona does not observe daylight saving time, with the exception of the Navajo Nation, which does observe DST. The Hopi Reservation, which is not part of the Navajo Nation but is geographically surrounded within it, does not observe DST.
The tz database version contains two time zones for Arizona:
CCCoordinatesTZCommentsUTC offsetUTC offset DSTNotes
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Example

When daylight saving is not active, the time in Phoenix and Denver is the same, and both are one hour ahead of San Diego.
When daylight saving is active, the time in Phoenix and San Diego is the same, and both are one hour behind Denver.