Skip to main content

You’ll feel tired Monday. Thanks, daylight saving time.

Losing just one hour of sleep can wreak havoc on internal body clocks

This Sunday we’ll lose one hour of sleep when our clocks spring forward for daylight saving time. Those missing 60 minutes of rest can wreak havoc on our internal body clocks, impairing our mood, alertness and performance, said Northwestern University circadian rhythm expert Kristen Knutson.

“When we experience a time change like daylight saving time or traveling across time zones, our internal biological clocks need to adjust, and it can take a day or two,” Knutson said. “So it is best to avoid scheduling important meetings or events on the Monday or Tuesday after the time change.”

Knutson, an associate professor of sleep medicine and epidemiology at Northwestern University Feinberg School of Medicine, is available for interviews ahead of the time change. Contact Kristin Samuelson at to schedule an interview. 

More quotes from Knutson:

“The March time change is harder for most people because it is easier to delay the clock than to advance it. For example, it is easier to wake up an hour later (delay) than it is to wake up an hour earlier (advance). The March time change also is harder because it often leads to sleep loss, which can also impair mood, alertness and performance.  

“Several societies, including the American Academy of Sleep Medicine and the Society for Research on Biological Rhythms, have published position papers in favor of abolishing daylight saving time. Additional information written for a general audience is available from the Sleep Research Society.”