Children’s circadian systems adjust to new time zones at roughly the same rate as adults’ — about one hour per day. For a 6-hour trip (US East Coast to Europe, say), you’re looking at 4–6 days for the child to fully adjust on either end. For a week-long trip, that means you essentially never fully adjust there before having to readjust back.

The practical strategies that work:

1. Pick your war

You cannot fight jet lag and maintain the home routine. Choose one. For a trip of 7+ days, fully adjust to local time. For a trip under 5 days, stay closer to home time and accept earlier nights.

2. Anchor with light

Light exposure is the single most powerful adjustment lever, far more than melatonin or meal timing. The rule:

Get the child outside in the right window each day, even briefly. The biological clock locks to the light pattern within 3–4 days.

3. Don’t fight the 3am wake-up

Children will reliably wake up at 3am for the first 2–4 nights after westward travel (or 3am-equivalent after eastward). Don’t try to put them back to sleep. Instead: keep the room dim, keep activity quiet, offer water, let them play softly until natural exhaustion returns. This is the night where parents most often try to “fix” the situation and end up creating a sleep association (rocking, parent’s bed) that lasts the whole trip.

4. Bring the anchor

The single object that travels well: the one specific book or stuffed animal that ends every bedtime at home. Brings the home ritual into the foreign hotel room. Five minutes of familiar trumps any clever travel-adjusted strategy.

5. Plan the return

The trip back is harder than the trip out, every time. Two practical moves:

For very young children (under 2), trips longer than 5 days across 4+ time zones are sleep-genuinely-disruptive. There’s no shame in waiting until they’re older for the long-haul vacation if you have flexibility.