How this calculation works
The Jet Lag Recovery & Sleep Reset Planner determines the number of days required for your biological master circadian clock (SCN) to resynchronize and provides timed bright light and melatonin protocols.
Mathematical formula and logic
Eastward Recovery Days ≈ Time Zones × 0.8 to 1.0 days/zone. Westward Recovery Days ≈ Time Zones × 0.5 to 0.7 days/zone.
Worked example
Crossing 6 time zones eastward (e.g. US to Europe) requires approximately 5 to 6 days for complete circadian adaptation. Crossing 6 time zones westward requires only 3 to 4 days.
Calculation assumptions
- Circadian pacemaker adjusts by ~1.0 hour/day traveling east and ~1.5 hours/day traveling west.
- Follows American Academy of Sleep Medicine (AASM) circadian light therapy guidelines.
Frequently asked questions
Why is flying east worse for jet lag than flying west?
Human internal circadian rhythms naturally run slightly longer than 24 hours (~24.2 hours). Extending the day traveling westward aligns with this natural tendency, whereas shortening the day traveling eastward forces the clock to advance against its natural rhythm ('West is best, East is a beast').
What is the single most effective tool to reset circadian rhythms?
Timed bright sunlight exposure is the strongest natural circadian cue (zeitgeber). Seeking morning outdoor light after eastward travel signals your brain to stop producing melatonin and advance your sleep schedule.
When should I take melatonin for jet lag?
Take a low dose of melatonin (0.5mg to 3mg) approximately 30 to 60 minutes before your target bedtime in the new local destination time zone for the first 3 to 4 nights.
Should I take naps during the day after a long flight?
Limit naps to a maximum of 20 to 30 minutes in the early afternoon. Taking long 2-3 hour naps destroys your homeostatic sleep drive and prolongs nighttime insomnia.
How does fasting help beat jet lag?
Fasting during the flight (12-16 hours) and having a high-protein breakfast at the normal local breakfast time upon arrival activates secondary metabolic peripheral food clocks in the liver, speeding adaptation.
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