How It Works

Your body has an internal clock (circadian rhythm) that takes time to adjust when you cross time zones. The general rule is that your body needs about one day per time zone to fully sync up with the local schedule.

But here’s the thing: direction matters. Flying east is harder than flying west because you’re basically trying to go to bed earlier than your body wants to. It’s easier to stay up late (flying west) than to fall asleep early (flying east). That’s why eastward flights typically need 50% more recovery time.

So if you cross 6 time zones going from New York to London, you’re looking at about 9 days to feel completely normal (6 × 1.5). But if you fly the opposite direction, it’s only 6 days.

What If I Cross More Than 8 Time Zones?

When you cross 9 or more time zones (like flying from Los Angeles to Tokyo), your body sometimes gets confused about which direction is shorter. Some people find it easier to adjust by thinking of it as going the “short way” around the clock instead of the long way.

For really long hauls (10+ time zones), many travelers report that the jet lag hits differently. Your body might actually adjust faster than expected because it’s almost like you’ve looped around to a similar time zone. But you’ll still feel wiped out from the flight itself, which is separate from jet lag.

Can I Speed Up Recovery?

Yes, but you can’t skip it entirely. The best thing you can do is get bright light exposure at the right times. If you’re flying east, get morning sunlight as soon as you arrive. If you’re flying west, get afternoon and evening light. This helps reset your internal clock faster.

Melatonin supplements can help if you take them at the right time (usually in the evening at your destination), but timing is everything. Taking it at the wrong time can actually make jet lag worse. Staying hydrated during the flight and avoiding alcohol also helps, though it won’t dramatically cut recovery time.

Some people swear by adjusting their sleep schedule a few days before the trip. If you’re flying east, try going to bed an hour earlier each night for three nights before departure. It won’t eliminate jet lag, but it can soften the blow.

What About Short Trips?

If you’re only traveling for 2 to 3 days and crossing fewer than 4 time zones, you might be better off just staying on your home schedule. Keep your watch set to home time, eat meals when you normally would (even if it’s odd hours locally), and power through with naps if needed.

This works for business trips where you’re flying out and back quickly. Your body won’t have time to fully adjust anyway, so you save yourself the double adjustment (there and back). Just expect to be a bit groggy during the local evening or morning hours.

Why Do Some People Handle Jet Lag Better?

Age plays a role. Younger people (teens to 30s) tend to adjust faster than older travelers. If you’re naturally a night owl, you might find westward flights easier. Morning people sometimes do better flying east, though the research on this is mixed.

Frequent flyers often report that they don’t get jet lag as badly after repeated trips on the same route. This might be partly psychological (you know what to expect) and partly physiological (your body learns the pattern). But even seasoned travelers still need recovery time, it just might feel less miserable.

Common Recovery Times

Does the Flight Duration Matter?

Not really, at least not for jet lag specifically. Jet lag is about time zone changes, not how long you spent on the plane. A 10-hour flight that crosses 2 time zones will give you less jet lag than a 6-hour flight that crosses 5 zones.

That said, longer flights leave you more physically exhausted, dehydrated, and stiff. This compounds the jet lag feeling, but they’re technically separate issues. You might feel terrible after a 14-hour flight even if you only crossed a few time zones, but that’s fatigue and dehydration, not your circadian rhythm being off.