‘Springing forward’ but taking two steps back: The hidden dangers of daylight saving time

After a long winter, the switch to daylight saving time on March 13 may seem like a welcome sign of spring.

But while many eagerly await more light in the evening, the negative consequences to “springing forward” can be far greater than simply 1 lost hour of sleep. In fact, the change to daylight saving time can result in negative impacts on our health that can linger for up to 7 days, according to an American Academy of Sleep Medicine (AASM) health advisory.

As we approach the start of daylight saving time, varying perspectives on seasonal time changes from the medical community, school districts and general public continue to capture attention. While differing views on the topic are inevitable, the sleep experts at the AASM recommend eliminating seasonal time changes and adopting permanent standard time as the best approach for public health and safety. Standard time most closely matches our circadian sleep-wake cycle, also known as the body’s internal clock.

Negative impacts of daylight saving time

A proliferation of evidence reveals the hidden dangers associated with seasonal time changes — and many are linked specifically to the switch to daylight saving time in the spring. The switch to daylight saving time causes the loss of an hour of sleep and results in more darkness in the morning and more light in the evening, which disrupts our body’s natural timing.

People with preexisting sleep disorders or those who regularly get insufficient sleep should be extra cautious, as they may experience the most serious adverse effects of the “spring forward.” Research shows the numerous negative health and safety concerns caused by daylight saving time include:

• an increase in car accidents and patient-safety related incidents due to human error the week following the time change;
• a higher risk of stroke and hospital admissions;
• elevated inflammatory markers, one of the body’s stress responses;
• an increased risk of mood disturbances; and
• disruption of the body’s circadian rhythm, or internal clock, impairing sleep quality and leading to sleep loss for up to 7 days.

The AASM position statement supporting the elimination of seasonal time changes notes that the adoption of year-round standard time aligns best with human circadian biology and provides distinct benefits for public health and safety. The statement is endorsed by more than 20 medical, scientific and civic organizations, including the American College of CHEST Physicians, American College of Occupational and Environmental Medicine, National PTA, National Safety Council, Society for Research on Biological Rhythms and World Sleep Society.

Legislative support for discontinuing seasonal time changes

In recent years, we’ve begun to see the emergence of widespread support for discontinuing the biannual time change from federal and state legislators. In 2021, Sen. Marco Rubio of Florida and several Republican and Democratic colleagues announced that they have reintroduced the Sunshine Protection Act in the U.S. Senate, which Rubio previously introduced as Senate bill 670 in March 2019. Like House bill 69, introduced by Rep. Vern Buchanan of Florida, the legislation would make daylight saving time permanent across the U.S.

While the AASM commends federal legislators for seeking to establish a national, fixed, year-round time and eliminate seasonal time changes, we encourage politicians to consider that shifting to permanent daylight saving time would lead to misalignment between the body’s daily rhythm and the timing of routine social obligations like work and school.

Tips to minimize the adverse effects of daylight saving time

To help Americans work through the inevitable fatigue caused by the switch to daylight saving time, sleep experts at the AASM recommend adhering to the following healthy sleep tips:

• Get at least 7 hours of sleep (for adults) or 8 hours of sleep (for teens) per night before and after the time change.
• Gradually adjust your sleep and wake times beginning 2 to 3 nights before the time change. Shift your bedtime 15 or 20 minutes earlier each night.
• For a few days before the time change, begin to adjust the timing of other daily routines that are “time cues” for your body. For example, start eating dinner a little earlier each night.
• On Saturday night, March 12, set your clocks ahead 1 hour in the early evening. Then go to sleep at your normal bedtime.
• Head outdoors for some early morning sunlight Sunday. The bright light will help set your internal clock, which regulates sleep and alertness.
• Go to bed early enough Sunday night to get plenty of sleep before the week begins Monday.

For those living with a chronic sleep disorder, such as obstructive sleep apnea or insomnia, it is even more critical to practice proper sleep hygiene, including implementing small changes in daily routines like keeping a consistent sleep schedule, minimizing exposure to screens or bright lights before bedtime, and avoiding caffeine, nicotine or alcohol in the evening hours. Most importantly, getting the recommended amount of 7 or more hours of sleep per night is crucial to maintain better health and outlook in our waking hours.

Help for an ongoing sleep problem is available from board-certified sleep medicine physicians and the team of health care professionals at AASM-accredited sleep centers. You can also find more information on sleep disorders and actionable healthy sleep tips by visiting SleepEducation.org.

References:

AASM health advisory: Daylight saving time. https://j2vjt3dnbra3ps7ll1clb4q2-wpengine.netdna-ssl.com/wp-content/uploads/2017/10/daylight-saving-time-sleep-health-advisory.pdf. Accessed March 8, 2022.

American Academy of Sleep Medicine calls for elimination of daylight saving time. https://aasm.org/american-academy-of-sleep-medicine-calls-for-elimination-of-daylight-saving-time/. Published Aug. 27, 2020. Accessed March 8, 2022.

Healthy sleep habits. https://sleepeducation.org/healthy-sleep/healthy-sleep-habits/. Accessed March 8, 2022.

H.R.69 — Sunshine Protection Act of 2021. https://www.congress.gov/bill/117th-congress/house-bill/69. Accessed March 8, 2022.

Rubio, colleagues reintroduce bill to make daylight saving time permanent. https://www.rubio.senate.gov/public/index.cfm/press-releases?ID=ACAE4503-822C-4C91-8C65-0C8B6F524053. Published March 9, 2021. Accessed March 8, 2022.

S.670 — Sunshine Protection Act of 2019. https://www.congress.gov/bill/116th-congress/senate-bill/670. Accessed March 8, 2022.