Jet Lag Calculator
Get a personalized day-by-day schedule for light, sleep, and caffeine. Built on the same circadian protocols used by elite travelers and chronobiology researchers.
9h eastward — your plan
9 phases- Pre-travel · Day -3-3d
Sleep 90 min earlier (21:30) and wake earlier (05:30). Get bright light immediately on waking.
- Pre-travel · Day -2-2d
Sleep 60 min earlier (22:00) and wake earlier (06:00). Get bright light immediately on waking.
- Pre-travel · Day -1-1d
Sleep 30 min earlier (22:30) and wake earlier (06:30). Get bright light immediately on waking.
- Travel dayDay 0
Hydrate. Set watch to destination time on boarding. Avoid caffeine within 8h of destination bedtime. Try to sleep on the flight.
- Recovery · Day +1+1d
Morning light 15–30 min on waking. Avoid bright light in the evening. Optional 20-min nap before 3pm. Caffeine before noon only.
- Recovery · Day +2+2d
Morning light 15–30 min on waking. Avoid bright light in the evening. Optional 20-min nap before 3pm. Caffeine before noon only.
- Recovery · Day +3+3d
Morning light 15–30 min on waking. Avoid bright light in the evening. Optional 20-min nap before 3pm. Caffeine before noon only.
- Recovery · Day +4+4d
Morning light 15–30 min on waking. Avoid bright light in the evening. Optional 20-min nap before 3pm. Caffeine before noon only.
- Recovery · Day +5+5d
Morning light 15–30 min on waking. Avoid bright light in the evening. Optional 20-min nap before 3pm. Caffeine before noon only.
Want this in your pocket?
BioLag turns this plan into daily notifications, adapts when you slip, and adds a full circadian schedule for non-travel days.
How the calculator works
The calculator compares your home timezone to your destination, then applies the standard chronobiology protocol: pre-travel shifting (30–60 minutes per day, up to three days before departure), an in-flight reset on boarding, and a recovery phase built around the strongest circadian lever — bright light timing.
Why eastward is harder
Your internal day runs slightly longer than 24 hours, so delaying sleep (flying west) is easier than advancing it (flying east). Expect ~1 day of recovery per timezone crossed going east, and ~1 day per 1.5 timezones going west.