Every spring, most Americans lose an hour of sleep, and every fall they get it back. Clocks on microwaves, cars, and wristwatches get reset. But in most of Arizona, nobody bothers. The clocks just keep ticking along the same way all year. Why is Arizona different?
The main reason is the heat. Daylight saving time shifts more daylight into the evening. In a place as hot as Arizona, that would push evening activities into earlier, hotter parts of the day and keep the sun beating down longer. Arizona opted out of daylight saving time in 1968 and has stayed on Mountain Standard Time year-round ever since, with one notable exception.
How Arizona Opted Out
Daylight saving time became official across the United States when the Uniform Time Act became law in 1966. But the law let states choose not to take part, and Arizona did.
The bill had been working its way through the legislature since January, backed by eleven state senators. On March 21, 1968, lawmakers passed the final version, putting the state on Mountain Standard Time all year. It passed the Senate 25 to 3 and the House 49 to 1, and Governor Jack Williams approved it the same day. Those lopsided votes show how little appetite there was for changing the clocks.
Why More Sunshine Isn't a Bonus
Daylight saving time works by setting clocks forward one hour during the long days of spring and summer, so evenings get more daylight and mornings get less. In cooler states, that extra evening hour feels like a treat. In the Arizona desert, it can feel like a punishment, stretching the hot afternoon even later. The state's hot climate is widely cited as the primary reason it stays on standard time.
There's an energy angle too. Daylight saving time was meant partly to save energy, but in Arizona it proved counterproductive. Longer sunny evenings meant people ran their air conditioners more, not less.
A Clock That Matches Different Neighbors
Because Arizona stays put while its neighbors change, its relationship to them shifts during the year. From November to March, Arizona's time matches Utah and New Mexico. From March to November, when the Pacific states spring forward, Arizona ends up on the same time as California and most of Nevada.
Arizona isn't alone, either. Hawaii also skips daylight saving time, along with U.S. territories such as Puerto Rico, Guam, and the U.S. Virgin Islands.
The Exception Inside Arizona
Here's where it gets tricky. The Navajo Nation, a semi-autonomous Native American territory that stretches across northeastern Arizona, northwestern New Mexico, and southeastern Utah, does observe daylight saving time. That way it keeps the same time across all its lands, regardless of state lines. So for part of the year, crossing onto Navajo land from elsewhere in Arizona means your clock jumps ahead an hour.
But inside the Navajo Nation sits the Hopi Reservation, which does not observe daylight saving time. The result is a real puzzle for travelers. Driving east on Arizona State Route 264 from Tuba City during daylight saving time can take you through six time changes in less than 100 miles.
So if you visit Arizona in the summer, double-check your watch, especially in the northeast. Elsewhere in the state, you can relax. The clocks stay the same, and the only thing changing is how hot it feels outside.
