What Sleep Researchers Actually Recommend Before Daylight Saving Time Hits

Twice a year, roughly a billion people across dozens of countries reset their clocks by exactly sixty minutes, and twice a year, sleep researchers give some version of the same interview. What should people do to get through it? Is there anything that actually helps? And, increasingly: why does this still happen at all?

The short answer to the first question, according to the sleep scientists and professional bodies who study this closely, is unglamorous: shift your schedule gradually in the days beforehand, get outside soon after waking once the clocks change, and don’t lean on caffeine or alcohol to paper over the disruption. The short answer to the third question is that the body most sleep researchers study for a living doesn’t tolerate abrupt one-hour jumps twice a year particularly well, and the professional organization representing sleep medicine in the United States has been saying so, on the record, for years.

What does the American Academy of Sleep Medicine actually recommend?

The American Academy of Sleep Medicine, the professional body that accredits sleep centers and sets clinical guidelines across the United States, published a position statement in 2020 calling for the elimination of the twice-yearly clock change altogether. The organization reinforced and expanded that position in an updated statement in 2023.

Its recommendation isn’t “pick whichever time you like better.” It’s permanent standard time, specifically. The AASM’s argument is that standard time keeps clock time closer to solar time: the sun sits roughly overhead near midday, mornings get earlier light, evenings get earlier dark, and this alignment matters because the human circadian clock takes most of its cues from light. Daylight saving time, by contrast, pushes clock time an hour ahead of solar time for roughly eight months of the year, which means later sunrises and later sunsets relative to the clock, all year, not just in the days right after the switch.

That distinction gets lost in a lot of casual conversation about “just picking one and sticking with it.” The AASM has been explicit that sticking with daylight saving time year-round is not what it’s asking for. When the U.S. Senate passed the Sunshine Protection Act in 2022, a bill that would have made daylight saving time permanent, the AASM publicly opposed it. Not because it objected to ending the twice-yearly switch, but because it objected to which time the switch would land on permanently. The bill stalled in the House and never became law, so the country is still switching twice a year as of this writing.

Why does the AASM think standard time is better than daylight saving time?

The core of the argument is biological, not political. Sleep researchers describe the body’s internal clock as running on a roughly 24-hour cycle that gets synchronized primarily by light hitting the eyes, especially in the morning. Under permanent daylight saving time, sunrise would arrive later, clock-wise, in the winter months, in some northern latitudes well after most people’s alarms go off. That delayed morning light is, in the AASM’s view, a chronic problem rather than a one-time inconvenience: months of dimmer mornings and later dusk, every year, indefinitely.

Standard time doesn’t create that mismatch. Mornings get light closer to when most people wake up, which is the signal the circadian clock is built to use to reset itself each day. The AASM’s position is that this daily alignment matters more for long-term health than the extra hour of evening light that permanent daylight saving time would provide, even though evening light is the part most people actually miss when the clocks fall back.

It’s worth being honest about what the underlying research can and can’t show. Much of the evidence linking the twice-yearly switch to elevated health and safety risks comes from population-level studies, comparisons of hospital admissions, traffic patterns, and workplace injury data around the transition dates, rather than controlled trials. Researchers in this area are generally careful to describe these effects as associations rather than proven causes of a fixed size. What’s more consistent across the data is the direction of the effect: outcomes worsen after the spring transition and don’t show the same pattern after the fall one. That asymmetry is a big part of why the AASM’s recommendation is standard time, not simply “no more switching.”

Who does the clock change actually hit hardest?

Not everyone feels the transition the same way, and the person who has done the most to explain why is Till Roenneberg, a chronobiologist at Ludwig Maximilian University of Munich who coined the term “social jet lag” to describe the routine mismatch between a person’s internal biological clock and the schedule society imposes on them: work start times, school bells, and, twice a year, an arbitrarily shifted clock.

Roenneberg’s broader body of work on chronotype, essentially whether someone’s internal clock runs naturally earlier or later than the social norm, helps explain why the same one-hour shift lands so differently from person to person. Someone whose body already wants to sleep and wake later than their schedule allows is, in effect, already carrying a version of what the clock change inflicts on everyone else. Spring forward adds an hour on top of a deficit some people were already running. That same mismatch, chronically running Monday through Friday rather than twice a year, is a bigger driver of ordinary sleep debt than most people who track it realize.

This is also, in a roundabout way, an argument for treating the clock change as more than a one-night inconvenience. If your chronotype already skews late, absorbing the full hour in a single night on top of your existing mismatch is a heavier lift than it is for someone whose natural rhythm already lines up closely with a 9-to-5.

What should you actually do in the days before the clocks change?

Sleep medicine guidance on this point is fairly consistent across the researchers and clinicians who write about it, and it isn’t complicated.

Shift gradually, not all at once. Rather than absorbing the full hour in a single night, move your bedtime and wake time by roughly 15 to 20 minutes a day for three or four days leading up to the transition, earlier for spring forward, later for fall back. By the time the clocks actually change, your body has already done most of the adjustment in small increments it can tolerate, rather than all of it in one disorienting jump.

Get bright light soon after waking, especially in the days right around the switch. Light exposure timing is one of the strongest levers for resetting the circadian clock, and morning light in particular helps anchor the new schedule faster than darkness or artificial indoor lighting does. Outdoor light is stronger than anything most indoor bulbs produce, so a short walk or even standing near a window shortly after getting up does more work than it seems like it should. The cortisol response your body produces in that first waking window is part of the same process; morning light exposure and that early hormonal surge reinforce each other, which is part of why researchers keep coming back to morning light rather than light exposure in general.

Go easy on caffeine and alcohol close to the transition, too. Both interfere with the sleep quality your body needs to actually adjust. Caffeine late in the day delays sleep onset further at exactly the moment you’re trying to move your bedtime earlier; alcohol fragments sleep in the second half of the night, which undercuts the consolidated rest that helps the circadian clock reset. Neither one has to disappear entirely; this is about timing, not abstinence, but both are worth being more deliberate about for a few days.

None of this is exotic advice. It’s the same logic sleep clinicians apply to jet lag and shift work: small, incremental adjustments beat abrupt ones, and light exposure timing does more of the actual resetting work than willpower does.

Is the spring transition really worse than the fall one?

Generally, yes, and the explanation researchers give comes down to which direction the shift runs. Falling back in autumn asks your body to stay up an hour later and sleep an hour later, a delay, which is roughly the direction most people’s circadian clocks already drift on their own if left unscheduled. Springing forward asks the opposite: fall asleep earlier, wake up earlier, on a clock that hasn’t caught up yet. That’s a phase advance, and it runs against the body’s natural tendency, which is part of why the population-level data on spring transitions tends to look worse than the data on fall transitions.

That doesn’t mean fall back is consequence-free. People with certain sleep disorders, shift workers, and anyone already running a sleep debt can feel either transition acutely. But if you’re trying to decide which side of the year deserves more preparation, the research points toward spring.

Will the twice-yearly switch actually go away?

Possibly, but not in the direction the AASM has been pushing for. The House passed the Sunshine Protection Act in July 2026, and it would lock in permanent daylight saving time, not the permanent standard time sleep researchers have actually been recommending — the twice-yearly switch could end soon, just not in the way the position statement above was arguing for. The AASM’s position statement remains, for now, a recommendation rather than policy. Sleep researchers have been making this argument for years without a change in the law.

That gap between what the evidence suggests and what actually happens twice a year is, frankly, why the practical advice matters more than it would in a world where the switch simply didn’t exist. Until legislation catches up with the research, most people are on their own for figuring out how to get through the transition without losing a week of function to it.

Where the plan usually breaks down

Everything above, the gradual shift, the morning light, the lighter hand on caffeine and alcohol, is easy to agree with and easy to abandon three days later. Shifting a bedtime by 15 minutes doesn’t feel urgent on day one, which is exactly why most people don’t do it until the night before, when it’s too late to be gradual about anything. The variables that actually predict whether someone follows through on a plan like this tend to have less to do with knowing what to do and more to do with whether anything outside your own intentions is tracking whether you did it.

So: if you already know the gradual-shift advice, and most people who’ve read this far do, will you actually move your bedtime 15 minutes earlier tonight, or is this the kind of plan that quietly doesn’t survive contact with a Tuesday? For a lot of people, the honest answer depends on whether something outside their own memory is keeping tabs, whether that’s a friend who asks, a habit tracker that logs it, or an app like DontSnooze that turns “I’ll adjust my alarm gradually this week” into something a little harder to quietly skip.