Does Arizona Have Daylight Saving Time?
No. Arizona has not observed daylight saving time since 1967. The state stays on Mountain Standard Time (MST, UTC−7) every day of the year. When the rest of the country "springs forward" in March, Arizona's clocks don't move — and they don't move again in November when everyone else "falls back."
How the Opt-Out Happened
The Uniform Time Act of 1966 standardized daylight saving time across the United States, but it included an escape hatch: a state could exempt itself by law. Arizona observed DST once under the new federal scheme, in 1967, and the experience was widely disliked. The legislature passed an exemption in 1968, and the state has skipped the clock change ever since. Hawaii made the same choice, which is why "except Arizona and Hawaii" appears in nearly every American explanation of DST.
Why the Desert Hates Extra Evening Sun
Daylight saving time exists to shift an hour of daylight into the evening. In most places that's a pleasant trade. In the Sonoran Desert it's the opposite of what anyone wants:
- Phoenix summer highs regularly exceed 110°F (43°C), and evenings are when the city becomes livable. Pushing sunset past 8:30 PM means an extra hour of punishing heat before things cool down.
- Later sunsets mean more air conditioning load in the evening, not less energy use — inverting DST's original rationale.
- Outdoor work and recreation in Arizona are scheduled around avoiding the sun, not maximizing it.
The Practical Effect on Arizona's Clock
Because Arizona holds still while its neighbors shift, its relative time changes twice a year even though its own clocks never do:
| Period | Arizona effectively matches |
|---|---|
| Mid-March – early November (DST elsewhere) | Pacific Time (Los Angeles, Las Vegas) |
| Early November – mid-March (standard time) | Mountain Time (Denver, Albuquerque) |
The live comparison table on our home page shows exactly where Arizona stands against every US time zone right now.
The One Exception: the Navajo Nation
The Navajo Nation, in the northeastern corner of the state, does observe daylight saving time — so for eight months of the year, part of Arizona is an hour ahead of the rest. The full story, including the Hopi enclave that follows state time inside it, is in our Navajo Nation time guide.
Could This Ever Change?
Congress has repeatedly considered making daylight saving time permanent nationwide — the Sunshine Protection Act passed the US Senate in 2022 before stalling in the House. If permanent DST ever became federal law, Arizona would face a choice: join it, or become the state that's an hour behind its current alignment year-round. Until then, Arizona's clocks stay put.