Daylight Saving Time: Two States Made “No More Switching” Permanent. Others Are Trying to Follow

On the second Sunday in March at 2:00 a.m., most of the United States still participates in a small ritual where the clocks jump forward by exactly one hour. For the average person, this transition is often viewed as a minor annoyance that costs a single hour of rest during a busy weekend. However, for lawmakers and sleep scientists, this recurring event is a live policy experiment that repeats on a rigid schedule every single year across the country.

While the majority of the nation adjusts their watches, two specific states will not take part in that synchronized jump when the calendar hits the spring date. Arizona and Hawaii already observe permanent standard time, which means their clocks do not shift for the start of daylight saving time at all. Residents in these regions maintain a consistent daily schedule throughout the year without the disruption of moving their clocks forward or backward.

This exemption from the national norm has started to matter significantly in statehouses located far beyond the borders of Phoenix and Honolulu in recent months. New bills continue to appear in various legislatures that aim to stop the clock-switching routine, even if lawmakers cannot yet agree on what that change should look like.

The Federal Framework for Time Changes

The debate over time zones often sounds like a simple fight over personal preference, but federal law sets strict boundaries for what states can actually do. The U.S. Department of Transportation explains that under the Uniform Time Act, states may exempt themselves from observing daylight saving time through their own state-level laws. If a state chooses to observe the shift, the start and end dates must follow the specific federally mandated schedule.

This legal detail creates a significant split that now shapes nearly every legislative proposal currently being debated by state representatives across the United States. A state can move to year-round standard time on its own authority, but it cannot unilaterally choose permanent daylight time without changes to federal regulations. The result is a crowded landscape of bills that frequently aim at the same target while attempting to use different legal levers.

The National Conference of State Legislatures tracks this legislative landscape closely, and its most recent tally shows how active the movement has become in 2025. The organization reported that at least 35 states have considered or are currently considering 93 separate bills or resolutions related to daylight saving policy. These measures are not confined to a single geographic region or a specific political party within the national landscape.

Scientific Warnings Regarding the Spring Shift

In many policy arguments, the one-hour change is sometimes treated as a trivial matter that people simply adjust to within a few days of the switch. In medical literature, however, the transition is treated as an acute biological disruption that can be measured through various health and safety metrics. A position statement published in the Journal of Clinical Sleep Medicine linked the spring transition to several measurable public health and safety risks.

The researchers found an abundance of accumulated evidence connecting the sudden shift to an increased risk of adverse cardiovascular events and mood disorders. The paper also highlighted how the transition can create a significant misalignment between the external light-dark cycle and the internal clock of the human body. This misalignment disrupts the timing of the circadian rhythm, which relies on consistent environmental cues to function properly for overall health.

Light is described in the research as the most powerful external cue, or zeitgeber, for regulating the rhythm of the human sleep-wake cycle throughout the day. When the clocks jump forward, it effectively forces a social schedule that is out of sync with the natural progression of the sun. This biological friction is the primary reason why many medical organizations have begun to advocate for a permanent end to the practice.

“Permanent, year-round standard time is the best choice to most closely match our circadian sleep-wake cycle,” said lead author Dr. M. Adeel Rishi of the Mayo Clinic.

The Biological Case for Morning Light

After laying out the various risks of switching, the American Academy of Sleep Medicine took a direct policy stance on the future of the American clock. The organization argued that seasonal time changes should be abolished in favor of a fixed, national, year-round standard time to protect public health. This recommendation is based on the way standard time aligns with human biology more effectively than the daylight saving alternative.

Dr. M. Adeel Rishi, a sleep medicine specialist, tied the medical argument to the presence of morning light and its effect on human alertness. He noted that daylight saving time results in more darkness in the morning and more light in the evening, which disrupts the body’s natural rhythm. This delay in morning light can make it harder for individuals to wake up and feel fully alert during their morning commute.

The position statement also addressed the fact that the chronic effects of staying on daylight time year-round have not been as thoroughly studied as the transition itself. However, the academy stressed that daylight saving time is fundamentally less aligned with human circadian biology because it delays the light-dark cycle relative to social schedules. This delay can lead to a condition known as phase delay, where the internal clock drifts later and later.

Measurable Impacts on Public Safety

The academy’s release included concrete numbers that advocates often cite during legislative hearings to demonstrate the tangible dangers of the current time-switching system. Studies indicate that traffic fatalities have increased by as much as 6% in the first few days after the spring change occurs in March. Furthermore, research abstracts have reported an 18% increase in adverse medical events related to human error in the week following the switch.

Public opinion data has also become a frequent part of the script used by lawmakers who are pushing for a permanent change to the law. A survey of more than 2,000 U.S. adults found that 63% supported eliminating seasonal time changes in favor of a national, fixed, year-round time. Only 11% of the survey participants opposed the idea of stopping the clocks, suggesting a broad consensus for a more stable system.

State lawmakers currently have clear examples of what opting out looks like by observing the daily operations of the two states that stayed behind. As more legislatures draft new proposals, the practical question becomes whether a state will do what federal law already allows by adopting permanent standard time. The phrase continues to reappear in bill language and health arguments as the primary solution for those seeking to end the biannual ritual.

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