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Transitioning to Standard Time: The Impact on Your Sleep and Health

It’s time to fall back, which means another hour of sleep. It’ll get darker earlier, but we’ll gain an hour of light in the morning. And while the early evening sunset may be dreaded, most sleep experts and organizations are in favor of keeping standard time permanent year-round. Here’s why.

It aligns with our circadian biology

Light is a critical synchronizer to our circadian rhythm. That’s because our bodies are automatically stimulated and cued with the timing of the sun. This is optimal for daytime functioning and nighttime sleep, according to the American Academy of Sleep Medicine (AASM).

Research shows that during Daylight Saving Time (DST), more people are sleepy in the morning and have trouble getting going. This is especially problematic for children.

"It’s harder for teenagers because their circadian rhythm undergoes a shift during puberty where they go to bed later and wake up later," says Kelly Glazer Baron, PhD, a clinical psychologist in Behavioral Sleep Medicine at University of Utah Health. "The problem with that is school start times are early, which makes it harder for them to wake up." But Baron points out that morning light can help their circadian rhythm.

It's good for your sleep health

Permanent DST would allow more darkness in the morning and more light at night, which misaligns our circadian rhythm to the environment—meaning we are going to bed later and getting up earlier than sunrise/sunset due to our everyday obligations. According to the AASM, evidence shows that the body clock doesn’t adjust to DST for several months. This could potentially cause sleep disruption and lead to chronic sleep loss.

Baron adds that if DST was permanent, it wouldn’t get light until 9:00 am in Utah some weeks during the year. And in the height of summer, it may push bedtimes later (for adults and children) because of late-night sunsets, especially in Western time zones.

It poses a public health and safety risk

According to studies, car accidents and drowsy driving increase at the start of DST. The transition can also be a health hazard for school-age children who catch a bus and walk or ride to school in the dark. "Permanent DST can have detrimental effects and serious consequences to missing out on that morning light," Baron says.

Transitioning between standard time and DST can increase your risk of:

  • Cardiovascular disease and events
  • Stroke
  • Mood disorders
  • Sleep disruption and loss

While most research shows the health impacts directly following the transition, there is little evidence of chronic or long-term effects of DST.

It can cause seasonal depression

As the days get darker and shorter, people may experience less energy and become less productive. Seasonal affective disorder (SAD) is a type of depression that is often triggered during the winter months. While symptoms range, people may have trouble sleeping, lose interest in activities they once enjoyed, feel hopeless, or have thoughts about self-harm. It’s important to seek help to help manage and treat symptoms of SAD.

It’s an easier transition for most

Parents can rejoice this time of year—not only for an extra hour of sleep, but because the transition to standard time shouldn’t negatively interrupt sleep schedules. "What was a 9:00 pm bedtime will now feel like a 10:00 pm bedtime," Baron says. "More than anything, people get more sleep for a couple days." And research shows a benefit to the time change with less heart attacks and car accidents.