Dec. 29, 2025 – The holidays can be an unexpected litmus test of how well your daily routine syncs – or doesn't – with your body's natural circadian rhythm.
It's called "social jet lag" – a term coined in 2006 by German sleep researcher Till Roenneberg – and it refers to the clash between your body's natural clock and your real-world sleep-wake schedule. Recent research links a persistent gap of at least two hours to weight gain, metabolic dysfunction, and heart problems. Classic symptoms are predictable: fatigue, daytime sleepiness, and low mood.
You're probably not going to develop social jet lag from one month of holiday revelry, but if you're already on the brink, it could push you over the edge.
"From an early morning turkey trot on Thanksgiving to late-night parties on New Year's, your body is being pulled socially in a lot of different directions," said Graham McGinnis, PhD, an associate professor at the University of Nevada in Las Vegas who studies how circadian rhythm disruption affects exercise performance. "The holiday time is a period when variability in behavior – especially important timekeeping cues [like light, mealtimes, and physical activity] really change."
Are You at Risk of Social Jet Lag?
Odds are yes. That's because most people's internal clocks are programmed to be just a bit longer than 24 hours. So we push our bedtimes later and find it harder to wake up early.
"What happens is that your work schedule gradually causes a decrease in how much sleep you get," said Joseph S. Takahashi, PhD, a circadian rhythm expert and professor of neuroscience at the University of Texas Southwestern Medical Center in Dallas.
A key driver is the social clock, which includes work, school, and other schedules that don't align with cues from the sun or our internal clock.
"For most people, with the workday and having to commute or get their exercise in, they do have to get up a little bit earlier than they naturally would, or go to bed a little bit earlier than they naturally would," said Kelly Baron, PhD, MPH, a University of Utah professor and clinical psychologist and an expert in behavioral sleep medicine.
Sleeping in two hours later on weekends versus workdays is a sign you're misaligned, sleep deprived, or – most likely – both, Baron said. Misalignment happens when your "chronotype" (science-speak for morning or evening person) clashes with your schedule – for example, being a night owl when you have early-morning commitments, or vice versa.
"Usually, if you're misaligned, that also means that you're sleep deprived," Baron said, "because you can drag yourself out of bed early, but you can't force yourself to bed earlier."
Weekend catch-up sleep is widely misunderstood as healthy, but for most of us, it's a flawed approach, she added. While some studies show benefits, these typically focus on people who are severely sleep deprived, making the benefits unlikely to apply to the broader population. Long-term outcomes are also uncertain: A 2025 study review found that weekend catch-up sleep could offer short-term relief, boosting mood and reducing fatigue, but may not erase the damage of ongoing sleep deprivation.
Understanding 'Holiday Jet Lag'
Strictly speaking, staying out later due to holiday activities (or getting up earlier when your kids rouse you to open presents at 5 a.m. on Christmas Day) isn't social jet lag. Those instances might be their own thing.
"Let's come up with a new term for it," Baron said. "Perhaps 'holiday social lag,' or 'holiday jet lag.' It is caused by social pressures."
Even sleep experts can be likely to get it. Takahashi said he has more holiday parties to attend than he can count. Baron and McGinnis said they'd be layering actual jet lag from cross-country travel on top of cramming work in amid holiday gatherings.
And there's another factor at play: "The days are shorter, and that means the synchronization of our clocks is weaker," Takahashi said. "So the social schedule can have a stronger influence."
How to Optimize Your Holiday Rhythm
Whether you call it "holiday jet lag" or "social jet lag," here are some expert-backed ways to lessen its effects:
- Avoid eating late. If you're attending an evening event, eat as soon as you get there. Mealtimes are one of the body's biggest timekeeping cues.
- Skip the nightcap. It's OK to have a drink or two, but give yourself a cut-off time to "minimize the damage" to your sleep, Baron said. "Sleep disruption with alcohol is related to when you drink it, and also how much. Alcohol consumed close to bed has a more detrimental effect."
- Don't go straight to bed. When you get home, "give yourself time to unwind, prepare yourself for bed, relax. It can be stressful to be going to so many different events or activities, and you do need transition time," said Baron.
- Exercise around the same time every day. Physical activity is a timekeeping cue for your body's internal clock, McGinnis said. A morning walk outside is a good option, since bright early morning light helps our body keep time.
- Be flexible. Don't obsess about a strict agenda. It's OK to stay out late a couple of nights or indulge at the buffet. "You don't need to be rigid," Takahashi said, but keeping a good sleep schedule with seven to nine hours of quality sleep per night will make you more ready for those big nights out.
