There is a particular kind of tired that arrives a day or two after you land. The flight is behind you, the bags are unpacked, and then your baby falls apart at 4pm and wakes up wide awake and ready to play at 3am.
After more than ten long haul flights with our two girls, I have been in that exact spot more times than I can count. So let me say this first: what you are seeing is jet lag doing what jet lag does. It is not a sign that your baby has forgotten how to sleep, and it is not something you have caused. If you are still in the planning stage, my tips for surviving a long haul flight with your toddler will help you get there in one piece. This article is about what happens once you arrive.
Here is why jet lag happens, what to expect in the first week, and the practical steps I use with families to help everyone land properly in local time.
Key Takeaways
- Jet lag happens because your baby’s internal body clock is still running on the time zone you left, and sunlight is the main thing that resets it.
- Babies under about 2 months make very little melatonin, so they are usually the least affected. From around 2 to 9 months, adjustment becomes more noticeable.
- A sudden slump around 4pm and a wake up around 3am to 4am are the two classic signs, and both are normal in the first few days.
- Morning light, a capped afternoon nap, and one consistent wake up time are the fastest ways to shift the body clock.
- Most families feel settled within about five to seven days. Some babies bounce back in two days and others take longer. Both are normal.
What causes jet lag in babies?
Jet lag happens when you cross time zones faster than the body clock can keep up. Your baby has a circadian rhythm, an internal 24 hour clock that tells them when to feel sleepy and when to feel alert. That clock is set mainly by sunlight. When you land somewhere the sun rises and sets at a different time, the clock is still running on home time, and everything feels out of step until it catches up. The Sleep Health Foundation explains the same process in adults, and light is just as powerful a signal for babies.
Where melatonin comes into it
Melatonin is often described as the day and night hormone. It rises in the evening as light fades and helps signal that sleep is coming.
Newborns under about 2 months produce very little melatonin of their own, so their sleep is driven far more by hunger and tiredness than by any sense of day or night. That is why very young babies often sail through a time zone change while the adults around them struggle.
From roughly 2 to 9 months, melatonin production rises and the body clock starts to hold a genuine pattern. That is when jet lag becomes something you actually have to manage, for your baby and for you.
Does your baby’s age change how much jet lag you notice?
Yes, quite a lot. Here is the pattern I see most often with families.
| Age | What is happening | What to expect with jet lag |
|---|---|---|
| Newborn to about 2 months | Very little melatonin of their own. Sleep is driven mostly by feeding and tiredness rather than a body clock. | Usually the easiest age to navigate this. Feed on demand and follow their lead. |
| About 2 to 9 months | Melatonin production rises and the body clock starts to hold a real pattern. | A genuine adjustment period. This is where the 4pm crash and the 3am wake up can show up. |
| 9 months and older | A well established body clock, plus firm habits and preferences around sleep. | Adjustment looks much like it does for us. Light and consistent timing can do the heavy lifting. |
What does jet lag look like in a baby?
There are two signs that show up again and again in the first few days after a long flight. If you know they are coming, they are far easier to handle.
- A sudden meltdown of tiredness around 4pm. Your baby seems fine, and then they are not. It can look a lot like the witching hour, except it is your baby’s body still expecting the middle of the night.
- Early waking, usually around 3am or 4am. Wide awake, cheerful, and completely convinced it is morning. I remember those mornings well, caffeine and toasties helped me through!
You may also notice shorter naps and shorter fuses for a few days, and your usual awake windows may not seem to align. All of this is jet lag, not a new sleep problem. It settles.
How do you help your baby adjust to a new time zone?
The aim is to give your baby’s body clock clear, consistent signals about what time it is in the place you have landed. Light, timing and routine do almost all of the work. These are the seven steps I take families through.
1. Follow the sun
The simplest rule is up at dawn, bed at dusk. Open the curtains in the morning and let the evening wind down as the light fades. The exception is winter travel. If the sun is setting at 5pm, do not push bedtime that early, or you will simply swap one problem for another.
2. Get out into the morning light
Early morning light is the strongest tool you have. Get outside soon after waking, even for fifteen or twenty minutes. A walk, a park, breakfast on a balcony, it all counts. Light in the morning tells the body clock that the day has started here, and it shifts faster than anything else you can do.
3. Plan for the late afternoon slump
Expect it, and let your baby nap. Just cap it at one sleep cycle, roughly 30 to 45 minutes, and wake them as you will likely need to. This bit gets pretty tricky as they get older and heavier! The point is to take the edge off without stealing from the night ahead. Then give them a stretch of awake time, feed, bath, and go down for the night. That first bedtime will probably be earlier than usual, and that is fine.
4. Ride out the early morning wake ups
Keep the room dark, keep it quiet, and keep stimulation low. No lights on, no play, no chat. A portable blackout blind is one of the most useful things you can pack. Be patient. Many babies will resettle if the environment gives them nothing interesting to wake up for. Or if you are like me, you could just lean into this and enjoy some early mornings together as it’s often short lived!
5. Shift bedtime later in small steps
Each day, move that early bedtime a little closer to your baby’s normal time. Small moves work better than big ones. You are nudging the clock, not resetting it in one go.
6. If bedtime is stuck too early
Sometimes bedtime lands at 5pm and refuses to budge. When that happens, keep your baby up an extra 15 minutes every two to three days until you reach the time you want. It feels slow, but it holds.
7. Set a consistent wake up time for your baby
This is the step families most often skip, and it is the one that makes the biggest difference. Wake up time and bedtime are the anchor points for the body clock, for babies and adults alike.
Pick a wake up time and stick to it, even after a rough night. When the alarm goes off, get your baby up. Open the curtains and add some bright light. Sleeping in feels kind in the moment, but it delays the adjustment for everyone and drags the whole thing out.
If you have a partner and you need the extra rest, you could try sharing the care here and taking turns to do the morning shift!
What should you do about naps while you adjust?
Be prepared to wake your baby from naps so they are not overdoing daytime sleep. It goes against every instinct, I know, but protecting the night is what gets you through this faster. If you want a refresher on what is typical for your baby’s age, I have written about how much sleep babies need and about catnapping.
You can also allow one extra nap a day while your baby is adjusting, then trim it back to their usual rhythm as things settle. Think of it as a temporary scaffold rather than a new routine.
How do you keep sleep safe when you are away from home?
Tiredness in an unfamiliar room is exactly when safe sleep slips, so it is worth being deliberate about it. As an INPAA Baby Safety Ambassador and a Red Nose volunteer, this is the part I never compromise on, at home or away.
- Use a portacot that meets the mandatory Australian standard, set up exactly as the instructions say. Red Nose Australia has clear guidance on portable cots.
- Use only the firm, flat mattress supplied with the cot. Do not add extra padding, toppers or a second mattress.
- Keep the sleep space clear of soft toys, pillows and loose bedding, and put your baby down on their back.
- Dress for the room you are actually in. Unfamiliar heating and hotter climates catch a lot of families out.
- Resist bed sharing as a shortcut when you are exhausted, particularly in an unfamiliar bed.
The Raising Children Network has more on sleep and travelling with children if you want to read further.
How long does baby jet lag last?
My honest answer is to plan for five to seven days of an adjustment period. Some babies are back to themselves within a couple of days. Others take longer. Both are completely normal, and neither says anything about your baby or about your parenting.
A few things that help while you wait it out:
- Keep your familiar rituals. The evening bath, the same sleeping bag, the same book, the same song. Consistency is what helps babies read the new local time.
- Expect a wobble when you get home too. The return trip is its own adjustment, and the same steps apply.
- Be kind to yourselves. This is not easy for anyone involved, and it does pass.
My mantra before any big trip is: let it go. Flexibility and patience will get you further than a perfect schedule ever will.
Frequently asked questions
Does jet lag affect newborns?
Far less than you would think. Babies under about 2 months produce very little melatonin, so they do not yet have a strong day and night rhythm to disrupt. Feed on demand, follow their cues, and start building local time into your own routine. In the early weeks, the adults usually have the harder time of it.
If I can only do one thing, what should it be?
Set one wake up time for the whole family and get straight out into the light. Those two together do more than everything else on this list combined. Wake up time is the anchor point for the body clock, and morning light is the signal that tells it the day has started here. Hold those steady, even after a broken night, and the rest tends to fall into place.
Should I wake my baby from their naps while we are adjusting?
Yes, if the nap is running long or falling late in the day. Capping the late afternoon nap at one sleep cycle, around 30 to 45 minutes, keeps enough sleep pressure for the night ahead. You can allow one extra nap a day during the adjustment and then reduce it back.
Next steps
- Flying soon? Read my seven tips for surviving a long haul flight with your toddler before you pack.
- Not sure what is typical for your baby’s age? Start with how much sleep your baby needs and awake windows.
- Travelling now and things have come unstuck? Book a free 15 minute chat and we can work out where to start.
- Phone and virtual consultations are available Australia wide and internationally. You can see all of my packages and pricing here.
