Daylight Saving Time and Its Impact on Sleep

Mar 11, 2024 | Blog

Daylight Saving Time (DST) is a practice many of us are familiar with, where we set our clocks forward by an hour in spring and back by an hour in fall. The goal? To make the most of the evening daylight and save on energy costs. But, have you ever wondered how this time change affects your sleep and overall health? Let’s dive into the science behind sleep, the effects of DST, and tips for adjusting to the time change.

The History of Daylight Saving Time

Since 1966, the majority of the United States has adhered to the practice of DST (Bryner, 2020). However, Hawaii, specific regions of Arizona, and U.S. territories including American Samoa, Guam, the Northern Mariana Islands, and the U.S. Virgin Islands do not observe DST.

The transition into DST occurs when we advance our clocks by one hour at 2 a.m. on the second Sunday in March, which effectively shortens that night by an hour (Rishi et al., 2020). Conversely, on the first Sunday in November at 2 a.m., we turn our clocks back by an hour. This practice is commonly known as “Spring Forward, Fall Backward” due to the seasonal timing of these adjustments.

The Science Behind Sleep and Daylight Saving Time

Adults need between seven and nine hours of sleep each night. Sleep is divided into two main types: non-rapid-eye-movement (NREM) sleep and rapid-eye-movement (REM) sleep (Cleveland Clinic, 2023). We cycle through these stages several times a night, with each cycle lasting about 90 minutes. Deep (NREM) sleep is crucial for feeling rested, as it’s when the body recovers and strengthens the immune system.

Our bodies follow a natural 24-hour cycle called the circadian rhythm, which helps regulate our sleep among other things. This internal clock relies heavily on daylight to keep us in sync (Reddy, Reddy, & Sharma, 2024). When we shift our clocks for DST, it can throw off this natural rhythm, leading to sleep issues and more.

Immediate Effects of Springing Forward

Losing an hour of sleep might not sound like a big deal, but it can have significant consequences. Research shows a spike in heart issues, mood swings, and even car accidents right after we “spring forward” (Zhang et al., 2020). This disruption in our biological clock can also lead to sleep deprivation and a host of related problems.

While our bodies can adjust to the time change after a few days, the long-term effects of DST are a cause for concern. Studies suggest that our bodies never fully adapt to this forced change, potentially leading to ongoing health issues like obesity, depression, and heart disease (Zhang et al., 2020). This chronic misalignment between our social schedules and biological clocks is often referred to as “social jet lag.”

Tips for Adjusting to Daylight Saving Time

Despite the challenges DST presents, there are ways to make the transition smoother:

  • Gradually Adjust Your Sleep Schedule: Start going to bed and waking up a bit earlier a few days before the time change (American Academy of Sleep Medicine, 2016).
  • Mind Your Diet: Avoid caffeine and alcohol close to bedtime, as they can disrupt sleep (Drake, Roehrs, Shambroom, & Roth, 2013).
  • Seek Out Sunlight: Exposure to natural light during the day can help reset your internal clock (Blume, Garbazza, & Spitschan, 2019).
  • Take Short Naps: If you’re feeling tired after the change, a brief nap can help, but keep it under 20 minutes to avoid feeling groggy (Lastella, Halson, Vitale, Memon, & Vincent, 2021).
  • Keep a Consistent Routine: Sticking to a regular sleep schedule can help your body adjust more quickly.

The Future of Daylight Saving Time

The debate around DST is heating up. Supporters argue it saves energy, reduces crime, and encourages outdoor activities (Doleac & Sanders, 2015). However, critics, including many health professionals, argue the health risks outweigh these benefits. They advocate for sticking to standard time year-round to better align with our natural rhythms.

Learn More

The shift to and from DST impacts our sleep and health more than we might realize. While there are strategies to help us adjust, the ongoing debate highlights the need for a closer look at the practice’s benefits versus its health implications. By understanding the science behind sleep and taking steps to minimize the impact of DST, we can better navigate these twice-yearly transitions. To learn more about the intricacies of sleep, visit our blog.

Sources:

  1. Bryner, J. (2020, March 5). Daylight saving time 2020: When we change our clocks and why. Live Science. https://www.livescience.com/56048-daylight-saving-time-guide.html
  2. Rishi, M. A., Ahmed, O., Barrantes Perez, J. H., et al. (2020). Daylight saving time: An American Academy of Sleep Medicine position statement. Journal of Clinical Sleep Medicine, 16(10), 1781–1784. https://jcsm.aasm.org/doi/10.5664/jcsm.8780
  3. Cleveland Clinic. (2023). Sleep basics. Retrieved from https://my.clevelandclinic.org/health/body/12148-sleep-basics
  4. Reddy, S., Reddy, V., & Sharma, S. (2024). Physiology, circadian rhythm. In StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK519507/
  5. Zhang, H., Dahlén, T., Khan, A., Edgren, G., & Rzhetsky, A. (2020). Measurable health effects associated with the daylight saving time shift. PLoS Computational Biology, 16(6), e1007927. https://doi.org/10.1371/journal.pcbi.1007927
  6. American Academy of Sleep Medicine. (2016, March 3). Health advisory: Daylight Saving Time. https://j2vjt3dnbra3ps7ll1clb4q2-wpengine.netdna-ssl.com/wp-content/uploads/2017/10/daylight-saving-time-sleep-health-advisory.pdf
  7. Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. Journal of Clinical Sleep Medicine, 9(11), 1195–1200. https://doi.org/10.5664/jcsm.3170
  8. Blume, C., Garbazza, C., & Spitschan, M. (2019). Effects of light on human circadian rhythms, sleep and mood. Somnologie: Schlafforschung und Schlafmedizin, 23(3), 147–156. https://doi.org/10.1007/s11818-019-00215-x
  9. Lastella, M., Halson, S. L., Vitale, J. A., Memon, A. R., & Vincent, G. E. (2021). To nap or not to nap? A systematic review evaluating napping behavior in athletes and the impact on various measures of athletic performance. Nature and Science of Sleep, 13, 841–862. https://doi.org/10.2147/NSS.S315556
  10. Doleac, J. L., & Sanders, N. (2015, December 8). Under the cover of darkness: How ambient light influences criminal activity. https://www.mitpressjournals.org/doi/abs/10.1162/REST_a_00547