Some of us are more vulnerable.
As natural night owls whose sleep cycles are already at odds with early school start times, teenagers can experience heightened sleep deprivation.
Individuals with heart conditions or those prone to anxiety and depression may experience exacerbated symptoms.
An epidemic of sleep deprived teenagers
More than 87% of high school students in the U.S. get far less than the recommended 8 to 10 hours of sleep.
Sleep and illness: The health risks of poor sleep
Did you know that one of the greatest risks to our immune system can be a lack of healthy sleep?
Each spring, the shift to Daylight Saving Time causes millions of people to lose an hour of sleep overnight. While one hour may not seem significant, the sudden change can disrupt the body’s internal clock and lead to several days of sleep disturbance. We believe understanding the science of sleep is the first step toward protecting your health and maintaining consistent, restorative rest.
The Body Runs on a Biological Clock
Human sleep patterns are regulated by the circadian rhythm, a natural 24-hour cycle controlled by the brain. This rhythm helps determine when you feel alert and when you feel sleepy, largely based on light exposure. When the clocks move forward in the spring, your body’s internal clock does not immediately adjust. As a result, many people experience difficulty falling asleep, waking up groggy, or feeling fatigued during the day (Harrison, 2013).
Researchers have found that it can take several days for the circadian rhythm to realign with the new schedule. During this adjustment period, people often experience reduced sleep quality, increased daytime sleepiness, and decreased cognitive performance (Lahti et al., 2006).
A Small Time Shift Can Have Real Effects
Studies have shown that the transition to Daylight Saving Time is associated with measurable changes in sleep duration and health outcomes. On average, people lose 40–60 minutes of sleep during the first few nights following the springtime change (Barnes & Wagner, 2009). Sleep researchers have also observed temporary increases in workplace errors, traffic accidents, and fatigue during this period as the body struggles to adapt (Fritz et al., 2020).
Some of these effects can be severe, including:
- Acute Cardiovascular Risk: The Monday and Tuesday after the shift show a 10% to 24% increased risk of heart attacks, largely due to the stress of lost sleep and biological clock misalignment.
- Sleep Loss and Fragmentation: The loss of one hour causes “mini jet lag,” reducing sleep quality and duration. Many people feel “groggy” or “cranky” for the entire following week.
- Accidents and Safety: Data indicates a roughly 6% increase in fatal car accidents in the days immediately following the shift, often referred to as “Sleepy Monday”.
- Circadian Mismatch: The shift forces a mismatch between our internal clock and the sun, with darker mornings and lighter evenings, making it harder to wake up early and harder to fall asleep at night.
- Mental Health and Productivity: The disruption can lead to mood swings, irritability, and lower productivity, with research even suggesting harsher judicial sentencing on the Monday after the shift.
These effects highlight just how sensitive sleep is to schedule changes. Even minor disruptions to our sleep cycle can affect mood, concentration, and overall health.
Supporting Healthy Sleep During the Time Change
While the clock shift is unavoidable, there are practical steps you can take to help your body adjust more smoothly:
• Shift your bedtime gradually – Move your bedtime 10 to 15 minutes earlier for several days before the time change.
• Get morning sunlight – Exposure to natural light helps reset your circadian rhythm.
• Maintain a consistent routine – Go to bed and wake up at the same time each day, even on weekends.
• Limit late-night screen use – Blue light from devices can delay melatonin production and make it harder to fall asleep.
• Prioritize a supportive sleep environment – Encourage your body to rest by turning off lights, blocking out sound, and making your sleep environment comfortable.
A Reminder to Protect Your Sleep
Daylight Saving Time is a useful reminder of how important consistent sleep truly is. Even a one-hour shift can influence energy levels, mood, and performance. By prioritizing good sleep habits and maintaining a supportive sleep environment, you can help your body adjust more quickly and continue waking up refreshed.
References
Barnes, C. M., & Wagner, D. T. (2009). Changing to daylight saving time cuts into sleep and increases workplace injuries. Journal of Applied Psychology, 94(5), 1305–1317.
Fritz, C., Lam, C. F., & Spreitzer, G. M. (2020). It’s the little things that matter: An examination of knowledge workers’ energy management. Journal of Applied Psychology, 105(1), 56–72.
Harrison, Y. (2013). The impact of daylight saving time on sleep and related behaviours. Sleep Medicine Reviews, 17(4), 285–292.
Lahti, T. A., Leppämäki, S., Lönnqvist, J., & Partonen, T. (2006). Transition to daylight saving time reduces sleep duration plus sleep efficiency of the deprived sleep. Neuroscience Letters, 406(3), 174–177.