Jet lag is your body clock still running on home time after a long flight. The NHS says it usually improves within a few days. Shorten the rough patch by shifting sleep beforehand and getting daylight at the right time when you land. A three-hour weekend lie-in is jet lag you paid for. At least this one comes with a holiday.
Jet lag in brief
Allow roughly a day per time zone to adjust (The Sleep Charity's rough guide), and expect flying east to be harder. Before flying, move your bed and wake times towards your destination's. On the plane, drink water, keep moving and sleep if it's night there. When you land, switch to local time, set an alarm, get outside in daylight and don't nap. For a 2 to 3 day trip, you could stay on home time.
Jet lag is your body clock running on home time
The NHS describes jet lag as your normal sleep pattern being disturbed after a long flight. You might struggle to fall asleep at bedtime or wake up in the morning, sleep poorly, feel tired and find it hard to stay awake during the day. Problems with concentration and memory are also among its main symptoms.
The Sleep Charity describes a mismatch between your body clock and local time: allow roughly a day per time zone, though most people manage differences of three hours or less without special measures. Westward travel is easier because your clock's natural cycle is slightly longer than a day. Eastman and Burgess report daily clock shifts of about an hour after flying east, versus an hour and a half after flying west.
Two flights cross the same number of time zones, one east and one west. Which usually brings worse jet lag?
- The flight east
- The flight west
- Neither, only the number of hours matters
Flying east shortens your day, and the body clock's natural cycle runs a little longer than 24 hours, so it adjusts more easily to a longer day going west.
Start moving your bedtime a few days before you fly
The NHS recommends plenty of rest before travelling and shifting bedtime and wake time towards your destination's time zone: earlier going east, later going west. Eastman and Burgess's worked example for an eastward flight moved the sleep schedule an hour earlier each day in the days before departure, with bright light in the morning. Pack your own pillow while you're at it, and if you need a new one, our pick of pillows has options.
On the plane, drink water, keep moving and sleep if it's night where you're going
The NHS gives a short list for the flight itself.
- plenty of water on board
- a stretch and a walk round the cabin
- sleep timed for night at your destination
- eye mask and earplugs packed, if they help you sleep
- caffeine and alcohol kept low: the NHS says both can make jet lag worse
Alcohol wrecks my sleep at the best of times, so the free drinks trolley is the easy one to wave past. Set your watch or phone to destination time as you sit down so you're thinking in local hours.
When you land, live on local time from the first day
When you arrive, the NHS says to switch your sleep schedule to the new time zone as quickly as possible.1 Set an alarm to avoid oversleeping and get outside during the day: natural light helps your body clock adjust. Don't sleep during the day. Daylight and regular meal times are what reset me, and if you're sleeping badly, skip the nap.
Get outside in daylight on your first day, and live on local time from the start.
Coming home is the same trip in reverse, so plan for it too. Use our sleep debt calculator to see how short you've run over the trip, and our sleep calculator to pick a bedtime for your first week back.
Time your daylight around 4am home time
The Sleep Charity's rough guide uses 4am in the time zone you left: bright light just before then pushes your clock later, which helps going west.2 Light a couple of hours after it pulls your clock earlier, which helps going east. Work out what 4am at home is in local time and plan your daylight around it. If that falls in the middle of your night there, sleep through it and get outside during the day instead.
The clocks going back each autumn feel like a mini jet lag to me, and morning light is the fix there too. For more on the darker months, see our guide to seasonal affective disorder.
The planner below works out the times for your trip.
Plan your body clock for the trip
Allow about a day per time zone. Before you fly, move your bedtime towards your destination's. When you land, sleep on local time, set an alarm and get outside in daylight.
On a two or three day trip, you could stay on home time
The NHS says that on a trip of 2 to 3 days, you could keep your eating and sleeping times on home time, so you don't have to change your schedule again when you get back. On a quick work trip, I'd keep my home bedtime and plan meetings around it where I can. If you're taking a long drive rather than a flight, see our road trip sleep tips.
Questions people ask about jet lag
The NHS says jet lag usually improves within a few days. It can't be prevented, but there are things you can do to reduce its effects. Direction matters too: Eastman and Burgess cite estimates from real travellers that the body clock shifts about an hour a day after flying east, compared with an hour and a half after flying west, so the same trip can feel different each way.3
The NHS does not recommend melatonin tablets for jet lag. It says there is not enough evidence to show they work, and medicines are not usually needed for jet lag. Instead, the NHS advises getting outside in daylight to help your body clock adjust and changing your sleep schedule to the local time as quickly as possible.
The NHS advises sleeping only at night and switching to the new schedule as quickly as possible. I'd hold out until a sensible local bedtime, even if you arrive wanting to crawl straight under the duvet. Struggling to stay awake during the day is one of the symptoms the NHS lists, so a flat first afternoon is normal.
