Beat jet lag with a plan made for your flight, free and with no sign-up. Pick where you fly from and to and your usual sleep times, and get a day-by-day schedule: when to shift your bedtime before you leave, when to get bright light and when to avoid it, and roughly how many days adjusting takes.
Planning the rest of the trip? Count down with the trip countdown, keep flights and hotels in My trips, and make the first day gentle in your day-by-day itinerary.
Yes. It is free with no sign-up, and it runs entirely in your browser.
Roughly one day per time zone crossed when flying east and a little less when flying west, because the body clock delays (stays up later) more easily than it advances. The calculator uses about 1 hour a day eastward and 1.5 hours a day westward.
East is usually harder: you have to fall asleep earlier than your body wants. West mostly means staying up later, which most people find easier.
Light is the strongest signal for the body clock. Bright light after waking moves it earlier (useful flying east); bright light in the evening moves it later (useful flying west). Avoiding light at the wrong time matters as much.
It helps for trips of 3 or more time zones: shifting bedtime and wake-up by about an hour a day for 1–3 days before you leave cuts the jet lag you arrive with. Choose “On arrival” if your schedule doesn't allow it.
Ask a doctor or pharmacist. Timing and dose matter and it is not suitable for everyone, so this calculator gives no melatonin doses.
Yes. Time differences are worked out for your departure date using your browser's time-zone data, so DST changes are included.
No. It is general guidance based on how the body clock responds to light and sleep timing. If you have a sleep disorder or a medical condition, speak to a doctor.