Two States Don’t Observe Daylight Saving Time—Here’s Why

For most Americans, the second Sunday in March marks the start of daylight saving time (DST), when the clocks move forward for an extra hour of sunlight in the evenings. The practice was first adopted as an energy-saving effort during World War I, but for a few places, like Arizona and Hawaii, the clocks never move.

DST first went into effect on March 31, 1918, but was short-lived. It was instituted again during World War II before permanently taking root after the passage of the 1966 Uniform Time Act. Daylight saving time’s current mid-March onset was adopted in 2007.

Yet the Uniform Time Act has long allowed for local exemptions from daylight saving time, and certain states and territories, especially hot and sunny ones, took advantage of that.

The last time Arizona observed daylight saving time was 1967. Although the state adhered to DST during World War I and World War II with the rest of the country, the state opted out of observation after wartime.

The main reason: the hot climate. “The reason I hear most often is simply that we don’t need another hour of sunlight in the heat of the summer,” meteorologist Jimmy Stewart once said.

In the height of summer, the sun rises in Phoenix around 5:15 a.m. and sets around 8 p.m. Mountain Standard Time. If the state observed DST, it would force residents to wait until late in the evening to participate in outdoor activities or work without the heat of the sun.

“[Data] clearly show that we must wait until about 9 p.m. DST to start any night-time activity such as drive-in movies, moonlight rides, convincing little children it’s bedtime, etc.,” a 1969 editorial in the Arizona Republic stated. “And it’s still hot as blazes!”

Additional data found that when the state changed its clocks, energy consumption and cost increased—in opposition to DST’s goal—because air conditioners had to run longer in the heat of the extended afternoon.

There is one exception in Arizona: The Navajo Nation observes daylight saving time to stay on the same clock as its members in Utah and New Mexico.

Hawaii tried daylight saving time once nearly 100 years ago, in 1933, but it only lasted for three weeks before the measure was repealed. Despite following daylight time with the rest of the U.S. during World War II, Hawaii opted out in 1967. The islands’ relative proximity to the equator means both sunrise and sunset happen around the same time each day, providing around 11 to 13.5 hours of daylight year-round. Observing Hawaii Standard Time also allows for the lifestyle of islanders to follow the flow of the sun, according to KHON-TV.

Other traditionally sunny locations that don’t observe DST include the American territories of American Samoa, Guam, the Northern Mariana Islands, Puerto Rico and the U.S. Virgin Islands. Like Hawaii, these islands get lots of sunshine throughout the day all year long, so there wouldn’t be much benefit to changing the clocks twice a year.

Although Indiana participates in daylight saving time now, the state adopted the system just 20 years ago. The state is already split across the Eastern and Central time zones, but before a statewide opt-in on DST in 2006, the time change was followed on a county-by-county basis, which made doing business confusing.