Jean Clare Sarmiento/KJZZ

The sun sets in Scottsdale in October 2018.

When most of the country is told  to adjust their clocks this weekend, Arizona doesn’t need to re-set anything. A KJZZ listener asked through our Q&AZ reporting project why doesn’t Arizona participate in daylight saving time.

Arizona has a long history of opting in and out of daylight saving (DST), which started in the United States in 1918 to create more sunlight in warm-weather months. (Clocks are adjusted in most of the United States and its territories the second Sunday in March and the first Sunday in November.)

The state originally participated in the time change, until there was a public outcry in 1967. 

Calvin Schermerhorn, a history professor at Arizona State University, said people were reluctant to pay for an extra hour of air conditioning.

“It means shifting the time to when the day is hottest so citizens promptly said, ‘No, we don’t want that,’ and Arizona opted out.”

ASU meteorologist Randy Cerveny says in the summer, Arizonans need less daylight, not more.

"Try to think here of what it would be like if we went on daylight savings time in Arizona, and the sun didn’t set until like 9 or 10 at night," he said. "I mean, we'd be frying. We'd be miserable!"

Arizona has been on Mountain Standard Time since 1968.

Oddities with the time-zone system

But there are many oddities with the time-zone system, even within Arizona. For instance, the Navajo Nation participates in the time change, but the Hopi Tribe does not. 

DST also is not observed in Hawaii, American Samoa, Guam, Puerto Rico or the Virgin Islands.

So, would it be easier to have one, universal time?

Schermerhorn said our circadian rhythms would throw a wrench in that plan.

“We’ll have to think and act more like computers and less like human beings where we have this internalized, cultural clock," said Schermerhorn.

For now, the time zones remain a suggestive rule and Arizona follows its own clock.

Efforts to end daylight saving time

Arizona and Hawaii aren’t the only states who don’t want anything to do with DST.

Three other states are in the process of detaching themselves from the biannual time change, but instead of opting out and following standard time, they want to stay in daylight saving time year round.

Florida, Tennessee and Oregon are at different points in the bill passing processes, but once it leaves a governor’s desk, the legislation needs federal approval.

Arizona did not need federal approval when they decided to stay in standard time year round. 

KJZZ's Naomi DuBovis contributed to this report.