Jet Lag Calculator & Adjustment Plan
Plan how to shift your sleep before and after a flight across time zones — how many days jet lag may last and a day-by-day bedtime schedule.
How to use
- 1Enter the number of time zones you're crossing and whether you're flying east or west.
- 2Enter your usual bedtime to get a pre-flight shifting plan.
How it's calculated
The body clock adjusts about 1 hour per day flying east and about 1.5 hours per day flying west. Shifting bedtime by 1 hour a day for up to 3 days before departure shortens the adjustment.
Frequently asked questions
Why is flying east harder?
Going east shortens your day, and the body clock finds it harder to advance (sleep earlier) than to delay.
What helps most with jet lag?
Timed light exposure: morning light after flying east, evening light after flying west. Staying hydrated and avoiding heavy alcohol helps too.
Should I take melatonin?
Some studies support low-dose melatonin at the destination bedtime for eastward flights. Ask a doctor or pharmacist first.