Daylight Saving Time – Why Some States Follow It and Others Do Not

Daylight saving time touches school mornings, evening commutes, business hours, and even public health outcomes.

Two states skip it entirely, several U.S. territories stay on standard time all year, and nearly every statehouse has debated changing it.

With new bills appearing every session and strong opinions on both sides, the topic has never been more relevant. Let’s get into the details.

How Daylight Saving Time Works in the U.S.

Most people know the clock jumps twice a year, but the details behind it can be a little hazy. Here’s a quick look at how the system actually operates across the country.

The Clock Changes

Every year, most of the United States shifts its clocks forward one hour on the second Sunday in March and back one hour on the first Sunday in November.

Those dates were set in federal law in 2007, after Congress extended the daylight saving period by several weeks.

If you’re unsure exactly when your clocks should change, you can always check the current time now for your region before adjusting.

The Legal Framework

The Uniform Time Act of 1966 established the foundation for daylight saving time. The U.S. Department of Transportation (DOT) oversees time zones and daylight saving policy because time standards directly affect interstate commerce, travel, and broadcasting.

Congress can modify the national framework, but states operate under two main options:

States cannot adopt permanent daylight saving time on their own. They must receive federal approval, which has fueled many bills that hinge on “effective upon federal authorization” language.

Who Observes Daylight Saving Time

Most of the country follows daylight saving time, but not everyone. Here’s a quick breakdown:

This patchwork reveals how local geography, history, and politics shape daylight saving decisions.

What States Are Allowed to Do

States don’t have free rein with daylight saving time, but they do have a few clear paths.

Before the debates heat up, it helps to see exactly what the law lets them change on their own and what still needs a green light from Congress.

Option 1: Stay on Standard Time

A state may exempt itself from daylight saving time altogether under 15 U.S.C. § 260a. Arizona and Hawaii have done exactly that, and territories have opted out as well.

In states spanning more than one time zone, exemptions can apply only to parts of the state in a specific zone.

Option 2: Pursue Permanent DST

States that want permanent daylight saving time can pass conditional laws, but they cannot act unilaterally. Congress would need to amend federal law or grant an exception.

Option 3: Adjust Time Zone Boundaries

Communities and counties can request a shift to a different time zone. DOT runs a rulemaking process, holds public hearings, and decides based on the “convenience of commerce.” These cases take about six months to a year and are relatively rare.

Where States Stand on Changing the Current Setup

Lawmakers revisit daylight saving time almost every session. Since 2018, at least 18 states have passed laws to observe daylight saving time year-round if Congress allows it. Those states include:

• 2018: Florida
• 2019: Delaware, Maine, Oregon* (Pacific Time portion), Tennessee, Washington
• 2020: Idaho* (Pacific Time portion), Louisiana, South Carolina, Utah, Wyoming
• 2021: Alabama, Georgia, Minnesota, Mississippi, Montana
• 2022: Colorado
• 2024: Oklahoma

As of 2025, the National Conference of State Legislatures reports that at least 31 states are considering daylight saving bills again, split between permanent standard time and permanent daylight saving time. The one point of broad agreement: frustration with changing the clocks twice a year.

Why States Take Different Positions

Geography and Morning Light

Latitude plays a powerful role. Northern states would experience extremely late winter sunrises under permanent daylight saving time.

For example, in parts of Minnesota or Montana, sunrise could come after 9 a.m. in midwinter. That affects school schedules, commuter safety, and sleep patterns.

Public health groups such as the American Academy of Sleep Medicine recommend adopting permanent standard time, which aligns better with human circadian rhythms and morning light exposure.

Their research suggests that morning sunlight is especially important for regulating sleep and mood.

Public Health and Safety

• Traffic risk after “spring forward.” Studies in Current Biology found a roughly 6 percent rise in fatal traffic accidents in the week following the March time change. That translates to about two dozen extra deaths nationwide each year.
• Mixed findings on heart health. Several studies link clock changes with small increases in heart attacks. However, a 2025 JAMA Network Open study found no significant increase, underscoring how results can vary.
• Long-term health models. Some modeling suggests permanent standard time could slightly lower risks of obesity and stroke by better aligning with natural light cues. Although effects per person are small, the scale of the population could make a difference.
• Public opinion trends. A 2025 Gallup poll found 54 percent of U.S. adults want to end the clock changes, with about half favoring permanent standard time.

Economics and Daily Life

Evening light benefits many industries, while early morning darkness can cause challenges.

• Retail and recreation. More daylight after work encourages outdoor activity and shopping. Golf courses, for example, rely on late-day tee times and have voiced concerns about revenue loss under permanent standard time.
• Crime rates. A Brookings analysis of the 2007 extension found fewer evening robberies when daylight saving time added more light later in the day, translating into tens of millions of dollars in social savings.
• School and work mornings. Later sunrises under permanent daylight saving time would complicate school bus schedules and morning shifts, particularly during winter. DOT hearings during the 1970s experiment documented these concerns extensively.
• Energy savings. The original pitch for daylight saving time was about conserving fuel and electricity. Modern evidence is mixed. The Department of Energy found only a tiny national savings from the 2007 extension, while Indiana’s natural experiment found about a 1 percent increase in residential electricity use after adopting daylight saving time.

Coordination With Neighbors

States prefer to move together to avoid confusion. Regional compacts are common. For example, a state may pass a bill that takes effect only if neighboring states adopt similar measures, reducing the risk of split time zones in metro areas.

The 1974 Experiment With Permanent DST

During the 1973 energy crisis, Congress enacted a trial of year-round daylight saving time starting January 6, 1974. Initially, public opinion supported it, but dark winter mornings soon proved unpopular.

News stories at the time highlighted children waiting for buses in pitch black conditions. Congress scaled back the experiment later that year, and the nation returned to the standard system in 1975. DOT reviews show ambiguous energy savings and mixed safety outcomes.

How States Can Change Their Approach Today

State lawmakers aren’t stuck with the status quo. Under current federal rules, they have a few clear paths to adjust how daylight saving time works locally, from opting out completely to setting up conditional laws that take effect if Congress makes changes.

Adopting Year-Round Standard Time

States can pass a law exempting themselves from daylight saving time, just as Arizona and Hawaii have done. Coordinating with neighboring states helps minimize disruption to commerce and broadcasting.

Pursuing Permanent Daylight Saving Time

Remind your congress members to ditch Daylight Saving Time for sleep health: https://t.co/ccKFiHF3K7

— Save Standard Time (@SaveStandard) May 21, 2025

States can pass conditional laws expressing intent to adopt permanent daylight saving time, but federal approval is still required.

The proposed Sunshine Protection Act, for example, would make daylight saving time permanent nationwide, but it has not passed Congress as of September 2025.

Adjusting Time Zone Boundaries

A county or region may petition DOT to switch time zones. DOT evaluates the request, invites public comment, and usually holds a local hearing.

This process typically takes 6 to 12 months and hinges on the “convenience of commerce” standard.

What Different Futures Could Look Like

Lawmakers and residents often picture two very different paths ahead. One locks in brighter evenings year-round, the other locks in lighter mornings. Each option reshapes daily routines, commerce, and health in its own way.

If Congress Made Daylight Saving Time Permanent

• Later winter sunrises across much of the country, especially in the North.
• Brighter evenings in winter, benefiting leisure and retail sectors.
• Potential mismatch with human circadian rhythms during winter mornings.

If Congress Made Standard Time Permanent

• Brighter mornings year-round, which sleep medicine groups argue better suits human biology and school schedules.
• Earlier sunsets all year, which some industries worry would cut into after-work activity and sales.
• Elimination of the spring “spike” in crash risk linked to the clock change.

Practical Takeaways for Residents and Organizations

From parents planning school mornings to business owners mapping out evening hours, a few clear takeaways can help turn policy debates into practical action.

Families and Schools

If you already find winter mornings too dark, permanent daylight saving time could extend that period even further. Permanent standard time would create brighter mornings but earlier sunsets year-round.

Employers and Shift Workers

Spring’s time change correlates with measurable increases in crash risk and sleep loss. Consider adjusting schedules or emphasizing fatigue management during that week to reduce risks.

Local Chambers and Recreation Businesses

More evening light aligns with increased after-work activity. If your region debates permanent standard time, model sales and staffing with winter sunset scenarios. Golf, tennis, and other outdoor industries often warn of revenue hits without evening light.

Policymakers

Weigh geography, commuter patterns, school timing, regional coordination, and the latest health evidence. DOT’s process covers time zone boundaries, but Congress still holds the key to changing daylight saving rules nationwide.

The Bottom Line

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Federal law sets the dates and the ground rules. States can stay on standard time all year without permission, which is why Hawaii, most of Arizona, and several territories skip daylight saving time.

States that want permanent daylight saving time can pass conditional laws but still need Congress to act.

Geography, sleep science, public safety, and economics all shape local preferences, which is why the map looks the way it does. The one area of consensus: fatigue with changing the clock twice a year.

It doesn’t matter if the country ultimately moves to permanent daylight saving time or permanent standard time will depend on how lawmakers balance darker winter mornings against brighter winter evenings, and which evidence they find most compelling.