ExploPractical
Jet lag and time zones: how to plan your first days
A practical plan for jet lag: how much time you will lose, what to do before you fly, on the plane and in the first days at your destination.
You can plan the visa, the flights and the hotel perfectly and still lose the first three days of a trip to a body that thinks it is 3 a.m. Jet lag is not a mystery, and a little planning shortens it.
This guide explains what causes it, how to judge the size of the problem before you book, and what to do before, during and after the flight. It is general travel advice, not medical advice. If you have a health condition, talk to a doctor before you change your sleep or take anything to help.
What jet lag is
Your body runs on a roughly 24-hour clock, set mainly by light. When you fly across time zones quickly, that clock stays on home time while the local clock jumps ahead or back. The mismatch causes tiredness, broken sleep, hunger at odd hours and a flat mood.
A common rule of thumb is about one day to settle for each time zone crossed. It is only a guide, and people vary a lot, but it is a useful way to think about how much of your trip the adjustment will use.
Measure the gap before you book
The size of the time difference tells you how seriously to plan:
| Time difference | What to expect | What to do |
|---|---|---|
| 1 to 2 hours | Barely noticeable | Shift your bedtime a little and carry on |
| 3 to 5 hours | A couple of groggy days | Keep the first day light and get outside |
| 6 to 9 hours | Several rough days, with night and day half swapped | Plan a buffer before anything important |
| 10 to 12 hours | Day and night are flipped | Start adjusting before you fly and arrive a few days early |
Daylight saving time shifts these numbers by an hour for part of the year, and countries change their clocks on different dates, so check the difference for your exact travel dates.
East is harder than west
Flying west gives you a longer day, and most people find it easier to stay up later than to fall asleep earlier. Flying east does the opposite: you land in the morning, with your body clock sure it is the middle of the night, and you must go to bed earlier than you naturally would. For the same number of hours, most people recover more slowly after flying east.
That is worth knowing when you choose a route. If you have a choice between a trip with a big eastward shift and one that goes west, give the first one more buffer.
Before you fly
- Move your sleep a little. If you can, shift your bedtime an hour or so earlier for an eastward trip, or later for a westward one, for a few days.
- Choose your arrival time. Landing in the daytime or early evening lets you stay up and go to bed at local time. Landing at 3 a.m. often costs a night of sleep and a day of fog.
- Start rested. A packed week before a long flight makes everything harder. Our trip checklist helps you get the admin done early so the last nights are calm.
- Pack for sleep. An eye mask, earplugs and a light layer help you sleep when it is night at the destination.
On the plane
- Set your watch and phone to destination time as soon as you board, and start behaving as if you are already there.
- Sleep when it is night at the destination, and stay awake when it is day.
- Drink water, go easy on alcohol and caffeine, and move around now and then.
The first days
- Get into the daylight. Light is the main signal that resets your body clock. Spend your first morning or afternoon outdoors, whatever the weather.
- Eat on local time. Meals at local times help your body match the new schedule.
- Keep naps short. If you must nap, keep it to 20 or 30 minutes and finish before mid-afternoon.
- Go to bed at the local bedtime. You may be tired early or wide awake. Lie down at a normal hour anyway.
- Do not drive while exhausted. Take a taxi or public transport for the first day.
Keep the first day light. Book nothing expensive and nothing that cannot be moved. Your plan is better when it has a soft landing.
Short trips and big gaps
For a stay of two or three days, some travellers choose to stay close to their home schedule and accept odd meal and sleep times, because adjusting fully would take longer than the trip. For longer stays, adjust to local time as fast as you can. If you have a fixed commitment, such as a meeting or a race, arrive a few days before it.
The timing of your trip matters too. Whether the weather is at its best affects how much you will want to be outdoors, which helps with the daylight tip above. See how to choose the best time to visit.
Time zones are odder than you think
- China uses a single time zone across the whole country, although it spans a very wide area.
- India is half an hour off the usual hourly steps, and Nepal is 45 minutes off.
- France has more time zones than any other country when you count its overseas territories.
- Clock changes happen on different dates in different places, so the gap between two cities can change for a few weeks each year.
Check the local time in Explo
Each country in Explo shows its local time on its page, so you can check it before you message someone or book a call. It is a small thing, but it prevents a lot of 4 a.m. phone calls. When you are choosing between destinations, you can also use it to see how big the shift will be, alongside the other facts that shape your shortlist.
