Many Americans welcomed the extra hour of sleep as clocks fell back on Nov. 1, marking the end of Daylight Saving Time. However, this seemingly harmless extra hour carries hidden health risks that most people are unaware of.
Research has well-documented the medical dangers of the springtime leap to DST, linking it to increased risks of atrial fibrillation, stroke, and worsening diabetes. The autumn fallback to standard time carries its own insidious toll: The abrupt change in the daily light cycle disrupts our circadian rhythm — the body’s internal 24-hour clock — which can cause a cascade of physical and emotional consequences that may last well into December.
Sunlight and darkness have a powerful impact on our circadian rhythm. When light enters the eye, the optic nerve sends a message to the brain’s hypothalamus, which controls the release of melatonin, the hormone driving our sleep-wake cycle. It also regulates cortisol and thyroid hormones, the chemical messengers governing our stress levels and metabolism.
According to medical experts, adequate morning sunlight is essential for aligning our circadian rhythm with the Earth’s 24-hour cycle. By interfering with this synchrony, the return to standard time may trigger widespread cellular and metabolic stress. Mental health can also be affected: A study published in the May 2017 Epidemiology found an 11% rise in the rate of depressive episodes immediately after clocks were turned back. Other clinical investigations have linked the autumn transition to increased insomnia, impaired concentration, and worsening chronic problems, such as inflammatory bowel disease.
Enacted during both World Wars to conserve fuel, Daylight Saving Time has faced repeated repeals due to public backlash. An attempt at year-round DST during the 1974 Energy Crisis was aborted when community groups rebelled against delayed winter sunrises that forced children to walk to school in freezing, pitch-black conditions. The schedule most people are familiar with today was set by the Energy Policy Act of 2005: Clocks advance to DST on the second Sunday in March and return to standard time on the first Sunday in November.
Currently, 48 states and Washington, D,C., participate in Daylight Saving Time. States have the right to opt out and remain on standard time permanently—as Arizona and Hawaii do. However, under the current federal mandate, no state can choose to remain on DST permanently.
Multiple polls, including Gallup, YouGov, and The Associated Press, have found that a majority of Americans favor ending the biannual shift. But there is an ongoing battle between factions that prefer permanent DST versus permanent standard time. Commercial and recreational industries such as the Hearth, Patio and Barbecue Association, and the National Golf Course Owners Association, lobby for year-round DST to extend afternoon light. Conversely, sleep scientists and medical organizations, including the American Academy of Sleep Medicine, advocate for permanent standard time, warning that fixed DST carries unique health risks including metabolic syndrome, obesity, and sleep disruption.
Research does show that year-round standard time aligns our circadian rhythm more closely with morning sunlight. A Stanford Medicine study projected that making standard time permanent would significantly reduce chronic diseases nationwide, preventing an estimated 300,000 strokes and 2.6 million cases of obesity.
According to Cornell Cooperative Extension, most farmers prefer year-round standard time: Their sun-driven work cycle follows natural daylight, rather than the clock. Switching hours upends planting, harvesting, and livestock schedules — especially complicating the daily milking of dairy cows.
National leadership is sharply divided over the issue. Secretary of Health and Human Services Robert F. Kennedy Jr. supports permanent standard time, even though the federal administration formally favors year-round DST. In July 2026, the House of Representatives approved the Sunshine Protection Act of 2025 to make daylight saving time permanent. Competing legislation was then introduced — the Sunshine for Our Kids Act of 2026 — which would mandate year-round standard time while still allowing states to choose DST. Both bills are currently stalled.
Amid this federal debate, states are launching their own initiatives: In January 2025, the New York State Senate established a task force of experts to study the impact of opting out of Daylight Saving Time altogether.
If you have new or persistent symptoms since returning to standard time — such as severe fatigue, blood pressure changes, palpitations, or depression — contact your primary care provider. If your symptoms are mild, these strategies may help:
- Set a daily routine: Arise, eat, exercise, and retire at the same time every day.
- Aim for seven hours of sleep nightly.
- Avoid operating heavy machinery within two weeks of the time change if you are tired.
- Avoid caffeine and alcohol.
- Spend time outdoors in the early morning. The light exposure can help normalize your circadian rhythm.
- Avoid looking at monitors or screens if you wake up early; wait until your usual wakeup time.
Some clock-shift symptoms can be prevented by preparing several days ahead: Get plenty of outdoor light during the day, and maintain a regular sleep-wake schedule.
Dr. Mary Jenkins, a contributor to the Herald and member of its board of directors, retired after nearly 40 years as a family practice physician in New York state.