- Daylight saving time comes to an end this Sunday.
- Gaining an hour can affect your circadian rhythm and potentially disrupt your sleep patterns.
- But if your sleep is disrupted for a long period of time, experts say you can get help.
Before going to bed tonight, many Americans will be setting their clocks back by an hour.
Daylight saving time officially comes to end at 2:00 a.m. on Sunday, Nov. 3, when standard time begins.
You might be looking forward to getting an extra hour of sleep that night, but the amount of rest that you get will depend in part on your sleep habits.
If you’re the sort of person who doesn’t wake up until your alarm clock rings, you might get some extra rest, but only if you go to bed at your normal hour.
“If you actually went to bed at your usual time and took advantage of it, yes, you possibly could get an extra hour of sleep,” Dr. Fariha Abbasi-Feinberg, FAASM, FAAN, the director of sleep medicine at Millennium Physician Group in Fort Myers, Florida, and a member of the board of directors of the American Academy of Sleep Medicine (AASM), told Healthline.
“If you actually got that extra hour of sleep, that could be greatly beneficial,” she continued, “but unfortunately, most people do not take advantage of that extra hour and instead decide to stay up and socialize or do other things.”
You might also get less than an extra hour of sleep if you’re a morning person who tends to wake up on your own, without an alarm. That’s because it can take several days or more for your body’s internal clock to adjust to the change.
“Those folks who tend to wake up before their alarm [goes off] will actually wake up and discover that, ‘Wow, I have a whole other hour until I need to go to work,’” Erik Herzog, PhD, a professor of biology and neuroscience at Washington University in St. Louis and president of the Society for Research on Biological Rhythms, said.
“Because if you think about it, there’s nothing that’s really changing in the environment. The sun is still coming up, the Earth is still rotating around its axis in the same way, and the only thing that’s changed is the clock on the wall,” he added.
After you roll your clock back, you might notice that the skies are lighter when you leave your home in the morning. On the other hand, the sun will set an hour earlier in the evening.
That could potentially affect the risk of traffic accidents, as drivers adjust to the change in light levels and visibility.
When scientists reviewed the research on traffic accidents following the autumn time change, they found conflicting results: a third of studies found that traffic accidents and injuries increased after the change, a third found that accidents and injuries decreased, and a third found no significant difference.
Some of the studies in the review found that pedestrians were more likely than motorists to be injured in traffic accidents after the return to standard time.
That might reflect the fact that pedestrians tend to spend more time outside in the evenings, which get darker an hour earlier after time change.
On the other hand, drivers who get extra sleep when they roll their clocks back may be more alert on the roads. This might help account for the fact that some studies have found that traffic accidents and injuries decline following the autumn time shift.
Although it may take a few days to adjust to the autumn time change, the “fall-back” transition tends to be gentler on the body than the “spring-forward” shift.
Both seasonal time changes can disrupt your sleep habits and circadian rhythm, creating a disconnect between your body’s internal clock and your daily schedule.
But the spring time change is more disruptive for many people, especially those who find it hard to wake up in the morning.
“The harder thing happens in spring, when we spring forward for daylight saving time,” Herzog said. “There you’re being asked to wake up an hour earlier, when your body schedule has been used to waking up an hour later.”
“For many of the late birds who struggle to wake up early in the morning,” he continued, “it has sort of chronic effects that persist for the time that they’re in daylight saving time.”
The shift to daylight saving time can rob a lot of people of sleep, which might help account for the link that some scientists have found between the spring time change and higher risk of heart attack.
When researchers in the Journal of Clinical Medicine pooled the results of seven studies, they found the risk of heart attack is significantly higher than average in the first week following the spring time shift. In contrast, they found no statistically significant increase in heart attack risk following the autumn time change.
Healthy sleep habits
If you’re someone who finds it difficult to adjust to the seasonal time change, planning ahead might help.
“Adjust your sleep time gradually,” Abbasi-Feinberg suggested, “by perhaps adjusting your bed time and wake time by 15 minutes every day.”
“If you can do this a few days in advance,” she continued, “then the night when you have to make the change tends not to be a big deal.”
Abbasi-Feinberg also encourages people to get bright light exposure when they wake in the morning, which can help retrain the body’s circadian rhythm.
For people who struggle to sleep at any time of year, practicing good sleep habits may help.
For example, the AASM recommends following a consistent sleep schedule, establishing a relaxing bedtime routine, and sleeping in a room that’s quiet and cool. Avoiding caffeine, alcohol, heavy meals, electronic devices, and bright lights before bedtime may also help.
“The AASM recommends that people get at least seven hours of sleep, and that sleep along with exercise and good diet is one of the pillars of good health,” Abbasi-Feinberg said.
“I recommend that people look at the change of seasons as an opportunity,” she continued, “and say, ‘I have the chance to improve my sleep habits — let’s do it.’”
If you still find it difficult to sleep or you feel chronically tired, even after adjusting your sleep habits, it may be time to make an appointment with a board-certified sleep specialist. They can help you learn if a sleep disorder or other medical condition may be disrupting your sleep.