Does Arizona Have Daylight Savings? No — With One Exception

Published 2026-07-16

No — Arizona does not observe daylight saving time and hasn't since 1968. The state stays on Mountain Standard Time (UTC-7) every day of the year. Clocks in Phoenix, Tucson, and Flagstaff never spring forward or fall back.

One exception: the Navajo Nation, which covers much of northeastern Arizona, does observe DST. And the Hopi reservation, which sits entirely inside the Navajo Nation, does not — a doughnut arrangement that lets a summer road trip cross clock changes several times without leaving the state.

The practical consequence: Phoenix keeps the same time as Los Angeles in summer and the same time as Denver in winter. If you schedule calls with Arizona, the offset you memorized in January is wrong by April.

Why Arizona opted out in 1968

The Uniform Time Act of 1966 standardized daylight saving time across the U.S., but it let states exempt themselves. Arizona tried DST exactly once, in 1967, and dropped it. The legislature passed the exemption the following year, and the state has run on permanent standard time ever since. The opt-out is still on the books as A.R.S. § 1-242.

The reason is heat. Phoenix tops 110°F in June, and daylight saving would push sunset from about 7:40 p.m. to 8:40 p.m. — an extra hour of full sun during the hours people are home running the air conditioning. In most states DST buys usable evening daylight. In the desert it buys more time waiting for the pavement to cool off.

The exception: the Navajo Nation observes DST

The Navajo Nation is the largest reservation in the country — about 27,000 square miles spanning Arizona, Utah, and New Mexico. Utah and New Mexico both observe DST, so the Navajo Nation observes it too, keeping one clock across the whole territory instead of splitting it at two state lines.

From March to November, that puts Window Rock, Tuba City, Kayenta, and Monument Valley one hour ahead of Phoenix, even though they are all in Arizona.

The Hopi doughnut: five time changes on one highway

Here is where it gets strange. The Hopi reservation sits entirely inside the Navajo Nation and follows the rest of Arizona: no DST. There is also Jeddito, a small Navajo community surrounded by Hopi land — which is itself surrounded by Navajo land. Jeddito observes DST.

Drive State Route 264 from Tuba City to Window Rock on a July afternoon and the local time flips at every boundary: Navajo (DST), Hopi (no DST), Jeddito (DST), Hopi again, then back onto Navajo land. Start the trip in Flagstaff and that's five effective time changes in one day of driving, all inside Arizona. A round trip doubles it.

Signage is sparse, and phone clocks near the boundaries jump depending on which cell tower they catch. Locals on both reservations routinely confirm appointments with "Navajo time" or "Arizona time" attached, because the bare hour is ambiguous half the year.

Phoenix time vs. everyone else, by season

Since Phoenix never moves, its offset from every DST-observing city shifts twice a year — on the second Sunday of March and the first Sunday of November. Arizona doesn't change; everyone around it does.

The summer row is the one that trips people up: for nearly eight months of the year, Arizona runs on what is effectively Pacific time. One footnote on London: the UK changes clocks on its own schedule — last Sunday of March and last Sunday of October — so for a few weeks each spring and fall the gap is 7 hours, not 8.

Scheduling calls with Arizona

Arizona is the state most likely to break a recurring meeting. A few rules that prevent it:

• Set calendar invites to the "Arizona" zone (America/Phoenix), not generic "Mountain Time." Some apps treat Mountain Time as Denver and will silently shift your meeting an hour in summer.
• A standing 9 a.m. Eastern call lands at 7 a.m. in Phoenix during winter and 6 a.m. during summer. Confirm before booking anything early.
• The risky weeks are mid-March and early November, when everyone else's offset to Arizona changes. A recurring meeting pinned to an Eastern or Pacific clock will move on Phoenix clocks those weeks.
• For a quick check of the current gap, the EST to MST converter handles the Eastern-side DST shift automatically.

Hawaii and everywhere else that skips the clock change

Arizona isn't alone. Hawaii opted out under the same Uniform Time Act provision and stays on standard time year-round — at 21° latitude, day length barely changes across the year, so moving the clock buys nothing. The U.S. territories skip it too: Puerto Rico, Guam, American Samoa, the U.S. Virgin Islands, and the Northern Mariana Islands all stay on standard time year-round.

Time zones and DST observance for the states are administered by the Department of Transportation, which maintains the official rules at transportation.gov. Everyone else in the contiguous U.S. still changes clocks twice a year — Arizona just watches.

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