flights and time
Jet Lag Calculator
Enter your route and arrival time to see how many time zones you are crossing, how long recovery usually takes in that direction, and what to do with light, sleep and meals.
Your flight
the damage
Your plan
- 1Three days before you fly, move your bedtime one hour earlier each night. Move meals with it.
- 2On the flight, sleep as early as you can and refuse the second meal service if it lands in your new night.
- 3You land in the morning. Get outside within an hour of clearing the airport, walk for at least forty minutes and eat a normal breakfast.
- 4For the first three mornings, get bright light within an hour of waking and avoid bright screens after nine at night.
- 5Cap naps at twenty five minutes and never after three in the afternoon. Drink water on a schedule, not when thirsty.
- 6Set alarms for the local morning from day one, even if the night was bad. Fixing the wake time fixes the rest faster than fixing bedtime.
What actually shifts a body clock
Light is the strongest signal, meals are second, and sleep timing is third. That order matters. Getting outside for forty minutes on the first morning does more than an extra two hours in bed. On a long haul arrival, the walk from the airport train into daylight is the treatment.
Planning the first day around the arrival hour
Morning arrivals are hardest and the most useful. Do not check into a dark room and lie down. Drop the bag, eat breakfast at the local hour, and walk. Evening arrivals are easier: eat something small, sleep at a normal local bedtime and set an alarm.
Build the rest of the schedule with the itinerary generator and check the clocks at home with the time zone converter. There is more on arrival day logistics in the trip planning guide.
Questions people ask
+How long does jet lag last?
Roughly one day per time zone flying east and about two thirds of a day per zone flying west. Six zones east is close to a week, the same six west is around four days.
+Why is flying east worse?
Your body clock runs slightly longer than twenty four hours, so stretching a day is easy and shortening one is hard. Flying east asks you to fall asleep before your body is ready.
+Does the first day matter most?
Yes. Daylight at the right hour on the first two days does more than anything else. Sleeping through the first afternoon is the single most common way people extend jet lag by days.
+What about melatonin and caffeine?
Caffeine before noon local time helps you stay up, and nothing after two in the afternoon. Melatonin use is a question for a pharmacist or doctor, and dose and timing matter more than the brand.
+Should I change my watch on the plane?
Change it as you board and start thinking in the destination time immediately, including when you eat. It sounds trivial and it makes the first day easier.