Flying from the US to Tokyo usually takes about a week to adjust, and the return trip is often the harder one. Because the time difference is so large, your body clock can adapt by shifting later instead of earlier, which makes the trip there behave more like westward travel than eastward.
Free toolJet Lag CalculatorDays to adjust, plus a shift-before-you-fly schedule.How big the shift really is
Japan doesn't use daylight saving time, so the gap changes with the US clocks.
| Route | Tokyo is ahead by | Same as being behind by |
|---|---|---|
| New York to Tokyo (summer) | 13 hours | 11 hours |
| New York to Tokyo (winter) | 14 hours | 10 hours |
| Los Angeles to Tokyo (summer) | 16 hours | 8 hours |
| Los Angeles to Tokyo (winter) | 17 hours | 7 hours |
That right-hand column is the key. Being 16 hours ahead lands you at the same clock time as being 8 hours behind. Your body doesn't know which way you flew. It only knows that daylight and bedtime are now showing up at odd hours, and it will shift whichever way is easier.
Why direction matters less on long trips
For short trips, direction matters a lot. Flying east forces your body clock earlier, which it resists, because it naturally runs a little longer than 24 hours. That's why east is usually worse.
Once the time difference gets close to 12 hours, though, going "earlier" and going "later" are almost the same distance. At exactly 12 hours they're identical. So for very large shifts, the body clock tends to take the route that suits it, which is usually the later one.
- LA to Tokyo: effectively an 8-hour delay. That's a moderate westward-style adjustment.
- New York to Tokyo: 13 hours ahead or 11 behind. Close to the 12-hour point, so it can go either way, though later is usually the easier route.
The catch: when you're near 12 hours out, light at the wrong time can nudge your clock the "wrong" way and slow things down. That's why timing your daylight matters more on these trips, not less.
How long it takes
Using the same rule of thumb as our jet lag calculator (about 1 day per hour when shifting earlier, and roughly 1.5 hours a day when shifting later):
| Route | If your clock shifts later | If it shifts earlier |
|---|---|---|
| LA to Tokyo (8 h delay or 16 h advance) | about 6 days | about 16 days |
| New York to Tokyo (11 h delay or 13 h advance) | about 8 days | about 13 days |
| Tokyo to LA (8 h advance or 16 h delay) | about 11 days | about 8 days |
| Tokyo to New York (11 h advance or 13 h delay) | about 9 days | about 11 days |
Read these as rough ranges. The practical takeaway: going to Asia, help your clock shift later. Coming home to the West Coast, you're doing an 8-hour eastward-style advance, which is the harder direction.
A plan for the trip over
Before you fly
Go to bed and get up an hour later each day for two or three days, and get bright light in the evening. This is the opposite of what you'd do for Europe, and it's much easier to pull off.
On the plane
Most flights from the US land in Tokyo in the afternoon or evening local time. When it's 11:00 PM in Tokyo, it's 7:00 AM in Los Angeles and 10:00 AM in New York (summer time). So:
- Early in the flight, stay awake if it's daytime in Tokyo.
- Late in the flight, doze if you can, but aim to arrive tired enough to sleep at a normal local bedtime.
The first few days in Tokyo
- Get daylight in the late afternoon and evening. That supports a later-shifting clock.
- Avoid bright light very early in the morning for the first couple of days. Sunglasses help if you're out at dawn.
- Expect to wake at 3 or 4 AM. Stay in bed with the lights off. Don't check your phone.
- Keep naps short. A 20-minute nap in the early afternoon is fine. Our guide to the best time to take a nap explains why timing matters.
A plan for the trip home
Coming back east across the Pacific is where people get hit hardest, especially to the West Coast.
- Get morning light at home, and keep evenings dim for the first few days.
- Wake up at your normal time, even after a rough night. Sleeping in keeps you stuck on Tokyo time.
- Cut caffeine by early afternoon. You'll be sleepy in the afternoon, but a late coffee makes the next night harder. Use the caffeine calculator to find your cutoff.
- Plan an easy first two days back if you can. No early meetings, no long drives while you're foggy.
Short trip? Don't fully switch
For a trip of three or four days, you'll barely finish adjusting before you fly home. Some travelers stay partly on home time, schedule the most important meetings when their body clock is sharpest, and accept a few odd hours. It also shortens the recovery on the way back.
About melatonin
Melatonin is often used for long-haul jet lag, but the right dose and timing depend on the direction of travel and your health. Check with a pharmacist or doctor before using it, especially if you take other medications.