Jet lag happens when fast travel across time zones desynchronizes your internal circadian clock from the local day-night cycle, leading to fatigue, poor sleep, and reduced concentration.

How long does jet lag last?

As a rule of thumb your circadian rhythm shifts roughly one hour per day, so a six-hour time change typically takes several days to fully adjust. Eastward travel is usually harder than westward.

Can a planner actually reduce jet lag?

Yes. A structured plan that times sleep, light exposure, and activity in the days before and after a flight can meaningfully shorten adjustment compared with doing nothing.

Is Jet Zzz free to use?

Yes. Jet Zzz is free to use in your browser, with no account required.

Jet Lag from Tokyo to New York: How Long & How to Beat It

Jet Lag from Tokyo to New YorkNew York runs 13 hours behind Tokyo — a westbound shift over a roughly 13-hour flight. Expect about 9 days to feel close to normal in New York.What to expectWestward shifts extend the day and align with the natural drift of the circadian rhythm, so most travelers find them easier than eastward shifts.Adjustment playbook

Stay up later than usual the night before.

Stay awake on the plane during New York daytime.

Get bright late-afternoon light on arrival; avoid bright morning light day one.

Late-afternoon caffeine is fine.

Open in plannerBuild a personalized day-by-day plan for Tokyo → New York with your dates, sleep profile, and fixed activities at Jet Zzz.