Nov 17

Jet lag Survival Guide: Traveling 1-3 time zones eastward

Traveling across time zones with a baby or toddler can feel overwhelming. While the adjustment to a new time zone isn’t always easy, your child’s circadian rhythm is adaptable, and with careful planning around light and dark exposure, you can help them adjust with minimal stress. This blog breaks down the science behind jet lag and offers practical strategies to tackle eastward travel.

We know that travel can be complicated beyond jet lag. For more tips and tricks, check out our travel survival guide here.

The Science

Jet lag occurs because our circadian rhythm, which regulates sleep and many other biological processes, struggles to keep pace with rapid shifts across time zones. While our internal clocks can adjust to small daily shifts, traveling across multiple time zones creates a significant mismatch between our biological and social clocks.

The circadian rhythm is naturally flexible, making small daily adjustments to stay in sync with the 24-hour day. For about 70% of people, the circadian clock runs slightly longer than 24 hours, while about 30% have a clock that runs slightly shorter. Imagine your internal clock as a watch that runs 12 minutes fast; you would need to reset it each morning to maintain accurate time. Your child's circadian rhythm needs to reset each day to keep sleep and waking aligned with the day.

How the Circadian Rhythm Adjusts

The circadian rhythm resets primarily through light exposure through the eyes. Morning light exposure shifts the circadian rhythm earlier, while evening light exposure shifts the circadian rhythm later. However, "morning" and "evening" are defined by your child’s internal clock—not the local time on your watch. Mis-timed light exposure can worsen jet lag rather than improve it.

This interplay makes eastward travel tricky. If your child is exposed to light too early relative to their biological clock, their adjustment may backfire. Understanding your child’s internal timing and controlling light exposure accordingly is key to successful adaptation.

Why Eastward Jet Lag is Challenging

When traveling eastward, your child’s biological evening and morning don’t match the destination's local time. For example, traveling to New York from Los Angeles will shift your child's biological clock three hours earlier. Putting your child to bed at 7:00 PM New York time will feel like 4:00 PM, leading to bedtime struggles or middle-of-the-night wakefulness. Similarly, waking your child at 6:00 AM New York morning would feel like waking up at 3:00 AM. As you can see on the chart below, the impact of light changes at some point in the middle of the night. Therefore light exposure at 6:00 AM in New York could inadvertently shift your child's circadian rhythm in the wrong direction.

This is why jet lag is hard. You have to think about what time it is in your child’s body and control light exposure relative to that time. There are also a few complications that come up when traveling eastward that don't happen when traveling westward.

First, red-eye flights aren't usually an option when traveling westward, but they are common when traveling eastward. Red-eyes are particularly problematic because they usually land early in the morning at the destination. This will not only disrupt your child's sleep on the plane, but it will also expose your child to light at the wrong biological time and could make it harder for your child to adjust.

Another unique issue that arises when you travel from the west coast to the east coast is that the sun rises much earlier on the east coast. If you don't have adequate blackout curtains at your destination, early morning sunlight could wake your child and throw off the whole day.

How should you manage eastward travel?

Preparing for the Trip

Avoid red-eye flights if possible, as they disrupt sleep and often expose your child to light at the wrong time.
Bring portable blackout solutions, like blackout shades, or cover windows with aluminum foil (obviously keep your baby away from window coverings for safety), to ensure your child’s sleep environment stays dark.

Next, evaluate whether you actually need to shift your child's schedule. If your trip is short (less than a week) or only spans one time zone, consider keeping your child on their home schedule. If you need to adjust your child's sleep, follow the steps below to make it as painless as possible.

Adjusting Sleep Patterns Before and During Travel

For 4–12-month-olds:

Adjust bedtime and wake time by 15–30 minutes earlier each day.
Keep it dim in the evening before bed.
Allow late social bedtimes initially (e.g., a 10 pm bedtime or later is fine, think about what time it is at home).
Gradually expose your child to morning light after their wake-up time to reinforce the new schedule.

Sample Adjustment for a 4- to 12-Month-Old

The chart below shows how to adjust your baby. Babies in this age range typically tolerate a 15- to 30-minute shift in their circadian rhythm each day. Start by putting your baby down at a later-than-usual social time and gradually move bedtime earlier. While this adjustment may feel odd socially, it’s essential for success. Trying to force an earlier bedtime too soon may result in your baby treating bedtime as a nap and waking up for an extended period during the night.

Additionally, you’ll likely need to wake your baby each morning to help shift their schedule earlier. As noted above, you don't want to wake your child at their normal wake time by the clock, but you should wake your child a little earlier each day to help with the adjustment. This might feel counterintuitive if your baby had a late bedtime the night before, but it’s important for adjusting their internal clock. After waking your baby, expose them to bright light to reinforce the shift. (As noted above, if light exposure is too early, it will be a problem. It's ok to expose your child to bright light at or just before their normal wake time at home.)

For Toddlers (12+ months):

Adjust bedtime and wake time by 30-60 minutes earlier each day.
Keep it dim in the evening before bed.
Allow late social bedtimes initially.
Gradually expose your child to morning light after their wake-up time to reinforce the new schedule.

Sample Adjustment for a Toddler Over 12 Months Old

The chart below shows how to adjust your toddler. Children in this age range can usually handle a 30- to 60-minute shift in their circadian rhythm each day. A key point to remember is that your toddler may not feel sleepy at a socially appropriate bedtime during the adjustment. Start by putting your toddler to bed at a later social time and gradually shift bedtime earlier each day.

If you attempt an earlier bedtime too soon, your toddler might resist sleep—this could look like repeated requests for attention, climbing out of bed, or simply being unable to settle. To ensure progress, wake your toddler each morning at a progressively earlier time and open the curtains or turn on bright lights shortly after they wake up to encourage their internal clock to adjust. (As noted above, if light exposure is too early, it will be a problem. It's ok to expose your child to bright light at or just before their normal wake time at home.)

Managing Naps

Naps are not driven by the circadian rhythm, so you have more flexibility when offering your child naps. Adjust nap times by the same increments as bedtime shifts. If your child had a difficult night, it's ok for naps to be longer than normal. Just be prepared to wake your child so that they can go to bed at the appropriate time relative to your plan.

What should you do to help your child shift westward when returning home?

We have a blog for that! Check it out here.

We know that travel can involve all sorts of other chaos. Check out our general travel tips in this blog. If your child regressed during travel, you can use this blog to get back on track.

As always, we are here to help. Let us know if you don't see a blog on an issue that you are facing by contacting us on social media or through info@babysleepscience.com (note that while our goal is to help, we can't keep up with personal questions via e-mail. It takes away from our time with our own little ones). If you are struggling, feel free to book a one-on-one consultation with us or check out our sleep training class or newborn sleep class. We developed these classes based on our work with parents and offer many different approaches to sleep problems. We have lots of positive feedback on the class and you can join our private Facebook or Instagram groups for extra support while taking our classes.

References

Arendt, J., 2009. Managing jet lag: Some of the problems and possible new solutions. Sleep medicine reviews, 13(4), pp.249-256.

Arendt, J. and Marks, V., 1982. Physiological changes underlying jet lag. British Medical Journal (Clinical research ed.), 284(6310), p.144.

Deacon, S. and Arendt, J., 1996. Adapting to phase shifts, I. An experimental model for jet lag and shift work. Physiology & behavior, 59(4-5), pp.665-673.

Roach, G.D. and Sargent, C., 2019. Interventions to minimize jet lag after westward and eastward flight. Frontiers in physiology, 10, p.927.

Akacem, L.D., Wright Jr, K.P. and LeBourgeois, M.K., 2016. Bedtime and evening light exposure influence circadian timing in preschool-age children: a field study. Neurobiology of sleep and circadian rhythms, 1(2), pp.27-31.

Akacem, L.D., Wright Jr, K.P. and LeBourgeois, M.K., 2018. Sensitivity of the circadian system to evening bright light in preschool‐age children. Physiological reports, 6(5), p.e13617.