As much of America shifts back to standard time, you might find yourself enjoying an extra hour of sleep. But, don’t forget to get outside and catch that morning sunshine; it can help you adjust your body clock more quickly.
Daylight saving time ends at 2 a.m. local time on Sunday, so remember to set your clocks back one hour before heading to bed. Standard time will last until March 8, when we’ll “spring forward” again.
Many people express frustration about the biannual time changes. The switch in spring tends to be tougher, and whatever sleep you might gain in the fall seems to vanish. Still, a lot of us feel a sense of loss at the end of daylight saving time—especially since the days are already getting shorter. When the clocks change, it might mean less daylight for outdoor activities after school or work.
Health organizations like the American Medical Association and the American Academy of Sleep Medicine have long advocated for keeping standard time year-round.
A recent study from Stanford University supports this view, indicating that the back-and-forth time changes can negatively impact health. The research suggests that while either time is better than the regular shifts, sticking with permanent standard time is slightly more beneficial due to its alignment with natural sunlight and human biology, or circadian rhythms.
Jamie Zeitzer, co-director of the Center for Sleep and Circadian Science at Stanford, compares the body’s clock to an orchestra, stating that every organ functions better when it is in sync with the central clock. More morning light and less evening light are crucial for maintaining this harmony. Frequent disruptions from time changes can slow down the body’s systems, like metabolism and immune responses.
Interestingly, most countries don’t observe daylight saving time. The dates for time changes vary, particularly in North America and Europe. In the U.S., states like Arizona and Hawaii stick to standard time throughout the year.
How the Body Reacts to Light
The brain relies on sunlight exposure to set its master clock, creating a circadian rhythm—a cycle that influences our sleepiness and alertness. This rhythm shifts as we age, explaining why many individuals become early risers or night owls.
Morning light helps reset this rhythm. By evening, melatonin levels rise, causing sleepiness. If there’s too much light in the evening, whether from the sun or screens, it can push back that melatonin surge, throwing off our cycles.
This circadian clock doesn’t only impact sleep; it also affects heart rate, blood pressure, stress hormones, and metabolism.
How Do Changes in Time Affect Sleep?
Since work or school schedules stay put during time changes, a one-hour shift can mess with your sleep schedule. The transition to daylight saving time in spring is often challenging, as darker mornings and brighter nights can hinder our ability to fall asleep at the usual time. The initial days are even linked to an uptick in car accidents and heart-related issues.
Some folks struggle with seasonal affective disorder, a depression often tied to shorter daylight hours and limited sunshine during fall and winter.
While some people adjust easily—like recovering from jet lag—time changes can strain shift workers whose schedules are already misaligned with natural light, or those who face other sleep deprivation challenges.
More than one-third of U.S. adults don’t get the recommended seven hours of sleep nightly, and more than half of U.S. teens fall short of the recommended eight hours during the week.
Chronic lack of sleep can lead to serious issues like heart disease, cognitive decline, and obesity, among other concerns.
How to Prepare for Time Changes
In both the fall and spring, shifting your bedtime by just 15 minutes over several nights can ease the transition.
Morning sunlight is vital for resetting your circadian rhythm for better sleep. If you can’t head outside, sitting near a window can be helpful.
Will the U.S. Ever Eliminate Time Changes?
A piece of legislation known as the Sunshine Protection Act, which aims to make daylight saving time permanent, has faced stagnation in Congress in recent years.
