Jet lag from Seoul to New York: what to expect

How long does jet lag last from Seoul to New York?

Your clock will adapt the long way round: later each day, not earlier.

Unaided, eastward shifts settle at around a day per time zone: about 10 days for this one. S6 S7

This plan targets 9 days.

That's what the plan aims at, not a promise — bodies vary.

For this trip that's 1 day sooner than the unaided estimate, on the effort level that fits around a working day.

On night one, the evening after you land, the plan's bedtime is 20:00, early by New York's clock, and it moves later night by night, reaching 23:00 by night 9.

Studies of aircrew point the same way: after large shifts, westward adaptation runs roughly 50% faster than eastward S6 S8. It's why the plan goes the long way round here.

What does the plan say for a typical Seoul to New York flight?

Departs

20:00 Seoul time

Lands

20:00 New York time

In the air

about 14h (estimate)

Light, the first full day

13:55–14:55 Seek bright light (delay shift)

Last caffeine, landing day

07:00 on the plane

Caffeine after landing

23:00–12:00 landing night into the next day

Nap after landing

21:30 Nap when you can lie down, up to 90 min

First night's sleep

20:00–04:00 the evening after you land

This example leaves Seoul at 20:00 in the evening and lands in New York at 20:00 in the evening, after about 14h in the air.

The flight time is our estimate for a nonstop from the distance, and the trip is set in January. It's the default traveler from the calculator: usually asleep 23:00 to 07:00, no melatonin, Real Life effort.

You cross the date line going the other way, so you land on the same date you took off.

In July the gap is 11 hours, not 10, because New York moves its clocks and Seoul doesn't.

The plan puts about 5 hours of sleep on board, from 15:00 to 19:30 New York time, ending half an hour before you land. What's left of that night becomes a nap on the ground at 21:30: "Nap when you can lie down, up to 90 min".

You land at 20:00 and stay up through the local night, apart from the 21:30 nap: at 02:00 in New York your body thinks it's 16:00 in Seoul, its afternoon. It adds a 30-minute nap at 09:15. The first full night comes the next evening, at 20:00.

The day before you fly, the plan keeps your morning dim, 07:00–09:00 Seoul time, and the sun is up in Seoul by about 07:46 in January, so plan on sunglasses for the commute.

Your last coffee on the plane is at 07:00 New York time. After you land the plan opens caffeine again at 23:00, until 12:00 the next day: at 23:00 your body thinks it's 13:00 in Seoul, the middle of its day, and the plan keeps you up through the night on purpose.

January days are short in New York: about 10 hours of daylight. In January the sun is up in New York from about 07:13 to 16:57, so the 13:55 light step the day after landing is daylight. Outside is the easy way to get it.

You land too late in the day for a light step on landing day, so the first one is the next day, at 13:55.

What helps after flying east to New York?

Because the plan moves your clock later, the light advice for westward trips applies here, even though you fly east: light before your body's low point, which usually means bright light in the evening and staying up a little later S1. Bright light first thing in the morning works against you. East vs west explains the mechanism, and the plan's light steps above already follow it.

And the flight home from New York?

New York to Seoul is the same 10 hours the other way, westward. It's the easier direction: about 7 days unaided, and the plan targets 6. Jet lag from New York to Seoul has the details.

More routes from Seoul

• Seoul to Los Angeles