The end to daylight saving time (DST) for the 2024 year is upon us. Clocks in most parts of the U.S. did the annual "fall back" routine by one hour in the early morning of Sunday, Nov. 3.
Standard time will last until March 9 when we will again “spring forward” with the return of DST. That springtime change can be tough on the body, but health experts say the fall change should be easier to adjust to.
However, as Alabama and other parts of the country lose an hour of daylight, many will likely feel the effects. This could be through a disruption in sleep schedule or daily routines, which could impact mood and mental health.
“The effects of losing an hour in the day are more than just seeing less sunlight,” said Dr. John Burkhardt, associate professor with UA’s department of psychiatry and behavioral medicine, to the UA News Center. “It is linked to adverse health effects such as increased stress, lower cognitive functioning, heart attack and stroke. It can disrupt an individual’s circadian rhythms, altering their sleep/wake cycle causing sleep debt, and hormone level changes.
Health experts say the downsides of the time change, for some, are leaving work in the dark or trying to exercise while there's still enough light. Some people with seasonal affective disorder, a type of depression usually linked to the shorter days and less sunlight of fall and winter, may struggle, too.
Some health groups, including the American Medical Association and American Academy of Sleep Medicine, have said it’s time to do away with time switches and that sticking with standard time aligns better with the sun and human biology.
“For individuals living with major depression, seasonal affective disorder or other mood disorders, this can be an unwelcome long dark period," explained Dr. Burkhardt. "For individuals affected by one of these disorders, it can be a frightening time as they believe the time change signals an imminent depressive episode or season.”
How the body reacts to light
The brain has a master clock that is set by exposure to sunlight and darkness. This circadian rhythm is a roughly 24-hour cycle that determines when we become sleepy and when we’re more alert. The patterns change with age, one reason that early-to-rise youngsters evolve into hard-to-wake teens.
Morning light resets the rhythm. By evening, levels of a hormone called melatonin begin to surge, triggering drowsiness. Too much light in the evening — that extra hour from daylight saving time — delays that surge and the cycle gets out of sync.
And that circadian clock affects more than sleep, also influencing things like heart rate, blood pressure, stress hormones and metabolism.
How do time changes affect sleep?
Even an hour change on the clock can throw off sleep schedules — because even though the clocks change, work and school start times stay the same.
That's a problem because so many people are already sleep deprived. About one in three U.S. adults sleep less than the recommended seven-plus hours nightly, and more than half of U.S. teens don’t get the recommended eight-plus hours on weeknights.
Sleep deprivation is linked to heart disease, cognitive decline, obesity and numerous other problems.
According to Burkhardt, less sunlight can lead some to experience depression and anxiety, fatigue, isolation, decreased drive, and in some cases, suicidal ideations. Below are his recommendations to combat the negative effects of shorter days:
- Go outside in the morning to help offset reduced sunlight exposure.
- Consider light therapy by using a light box to counter the effects of decreased light exposure.
- Practice good sleep hygiene and maintain your current sleep schedule and daily routines.
- Stay physically active.
- Track your personal experiences and make necessary adjustments.
If you or a friend or colleague struggle with seasonal affective disorder or other mood disorders, connect with the UA Counseling Center or other resources on campus for support.
