Jet Lag Recovery Calculator
How many days to adjust, and when to seek light.
Enter your values
Results update instantly as you type — no submit needed.
Results
- Days to fully adjust
- 9.1 days
- Adjustment speed
- 40 min per day
- Seek bright light
- Early morning at your destination
- Avoid light
- Late evening
Quick answer
The body clock shifts about one hour per day westward and 40 minutes per day eastward, so eastward travel takes longer to adjust to.
How to use the Jet Lag Recovery Calculator
- 1Enter how many time zones you are crossing.
- 2Choose the direction of travel.
- 3Follow the light exposure guidance.
Frequently asked questions
Why is eastward harder?
The natural human circadian period is slightly longer than 24 hours, so delaying (westward) is easier than advancing (eastward).
Does melatonin help?
Low doses timed to the destination evening can speed eastward adjustment; discuss timing with a clinician.