Why crossing time zones wrecks your sleep, and a practical 48-hour plan to land sharp instead of foggy.
Jet lag is not just tiredness: it is your internal clock pointing at the wrong time zone. Your body runs on a roughly 24-hour circadian rhythm tuned by light. Fly across several zones and that clock lags behind, which is why the first two nights are the hardest.
Eastward is harder than westward
Flying east (e.g. US → Europe) shortens your day, forcing your clock earlier, the direction it resists most. Flying west lengthens the day, which is easier to absorb. A rough rule: budget about one day of recovery per time zone crossed.
Know the gap before you fly
Set your destination clock the moment you board, and start living on it. Seeing both times side by side makes "should I sleep now?" obvious:
A 48-hour light & sleep plan
Light is the strongest lever. Seek it or avoid it at the right hours and your clock shifts faster. This plan adapts to your specific flight:
Paris → Tokyo
출발 전 수면 조정
- 동쪽은 더 힘듭니다: 하루가 짧아집니다.
- 며칠 전부터 매일 약 1시간 일찍 자고 일어나세요.
- 도착 후 아침 햇빛을 쬐고 늦은 저녁 빛은 피하세요.
- 낮잠은 오후 3시 이전에 짧게. 도착일엔 야외로 나가세요.
Pack so arrival is painless
| Carry-on essential | Why |
|---|---|
| Refillable water bottle | Cabin air is desert-dry; dehydration mimics jet lag. |
| Eye mask + earplugs | Control light and noise to nap on destination time. |
| One change of clothes | If bags are delayed, you still feel human. |
Double-check what you can actually bring on board before you pack:
| 항공사 | 기내 | 위탁 |
|---|---|---|
| IATA guideline | 7 kg, 55x40x20 cm | 23 kg, 158 cm total |
| Emirates (Economy) | 7 kg | 30 kg |
| ANA (Economy) | 10 kg | 23 kg x 2 |
| Delta (Economy) | 1 bag + personal item | 23 kg (fee) |
참고용입니다. 항공사에 꼭 확인하세요.
On the plane
- Set your watch to the destination immediately.
- Skip the "free" alcohol: it fragments sleep.
- Walk the aisle hourly; move your ankles often.
- Eat on the destination's meal schedule when you can.
Land, get outside into daylight, and resist the 4 p.m. nap. You'll be on local time by day two, ready for the itinerary you built in voyageons.
Search questions answered
Readers asking “how long does jet lag last,” whether a short flight can cause it, or what recovery looks like from the USA to the UK will find the practical timeline here: symptoms often improve over several days, but the exact duration depends on time zones, direction and sleep timing.
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