As the clock winds down to 2 a.m. local time on Sunday, November 3, Americans will gain an extra hour of sleep when daylight saving time comes to an end. However, this seasonal shift also means that daylight will fade earlier in the afternoon, plunging many parts of the U.S. into darkness by late afternoon for the next few months.
With the transition to standard time lasting until March 9, when the clocks will “spring forward” again, experts warn that this time change can disrupt the body’s internal clock. While “falling back” is generally easier than the spring shift, it can still take time for individuals to adjust their sleep habits. The adjustment period can be particularly challenging for those who struggle with seasonal affective disorder (SAD), a type of depression linked to shorter days and reduced sunlight.
Health organizations, including the American Medical Association and the American Academy of Sleep Medicine, have advocated for eliminating the twice-a-year time change, arguing that standard time aligns more closely with natural light cycles and human biology.
Understanding Circadian Rhythms
The body’s response to light is crucial to understanding how time changes affect sleep. Our brains contain a master clock that regulates circadian rhythms—a roughly 24-hour cycle that influences sleep patterns, alertness, and various biological processes. Morning light helps reset this clock, while evening light triggers the release of melatonin, the hormone responsible for inducing sleepiness. The added hour of evening light from daylight saving time can disrupt this process, leading to a misalignment of the sleep-wake cycle.
This misalignment can have broader implications, affecting heart rate, blood pressure, stress hormones, and metabolism, according to experts.
Impact on Sleep Habits
Even a minor change in time can significantly disrupt sleep schedules, especially when work and school start times remain constant. This is particularly concerning given that about one in three U.S. adults do not get the recommended seven or more hours of sleep each night. Furthermore, over half of U.S. teens fail to achieve the recommended eight hours on school nights.
Preparing for the Change
To mitigate the effects of the upcoming time change, some individuals opt to adjust their bedtime incrementally in the days leading up to the shift. Experts recommend getting more exposure to sunlight, as this can help reset circadian rhythms and promote healthier sleep patterns.
Future of Daylight Saving Time
There have been occasional legislative efforts to eliminate the time changes altogether. One of the most notable recent proposals was the stalled bipartisan Sunshine Protection Act, which sought to make daylight saving time permanent. However, health experts argue that the focus should be on making standard time permanent instead.
As Americans prepare for the time change this weekend, it’s essential to be mindful of the potential impacts on sleep and overall well-being.
