Clocks are scheduled to “spring forward” one hour Sunday for daylight saving time, a bi-annual ritual that sleep experts warn can put circadian rhythms out of sync.
“The circadian rhythm is a network of body clocks that act throughout our body to control functions like sleep, metabolism, cognition, [and] immune function,” said Dr. Melissa Knauert with the Yale School of Medicine. “The circadian rhythm knows what time it is based on important environmental cues such as light.”
The Knauert Lab at Yale investigates sleep deprivation and circadian rhythm disruption in critically ill patients. Kanuert’s research shows that sleep deprivation and circadian disruption are likely key factors in the development of ICU delirium.
Among the general population, when clocks spring forward Sunday, people are essentially asking their bodies to shift one hour, which it cannot do immediately.
“If our body was used to going to sleep at 10 p.m. during standard time, it will now be used to going to sleep at 11 p.m when the clock springs forward by an hour,” she explained. “Therefore immediately on Sunday night after the switch, we are unable to go to sleep at our normal time and most people will miss an hour of sleep because there is no change in Monday wake up time.”
Over the coming week, circadian rhythms would slowly shift and return to matching one’s normal sleep wake timing – in this example, it would slowly shift back from 11 p.m. to 10 p.m., she said.
Knauert’s 3 tips to maintain a natural circadian rhythm all year long
- Keep a regular wake time on workdays and non-workdays.
- Expose yourself to bright morning/daytime light and avoid evening/nighttime light.
- Eat meals at regular times and avoid eating before your normal wake up time or after your normal bed time.
Certain populations at risk
Brianna Garrison, assistant professor of social work at Southern Connecticut State University, works with populations most affected by poor sleep – the elderly who have a higher cardiovascular risk, teenagers and people with mood disorders.
“Our bodies are meant to follow the sun, our circadian rhythms,” she said.
“And so when the sun is up later, we tend to want to stay up later, and then go to bed later. And then we’re waking up in the dark. So everything’s kind of off-kilter.”
Teenagers in particular are affected by the bi-annual clock change, Garrison said.
“Sleep is so developmentally important for our brains and teenagers are often the ones that are up early to be in school, and then have sports late at night,” she said. “And so these changes in the sleep patterns can really affect their ability to learn during the day, to be responsive as new drivers.”
More tips to manage the clock change
- Shift your bedtime 15 to 20 minutes earlier each night for a few nights before the time change, or right after.
- Get early morning sunlight on Sunday morning – the exposure will help regulate your morning routine.
Connecticut lawmakers have tried – unsuccessfully – to introduce proposals to end the bi-annual time change. A Gallup poll in 2025 found that the majority of Americans were ready to sunset the practice.
