Day-by-day plan
Pre-travel entries use home local time. Arrival and adaptation entries use destination local time. Light windows are conservative directional windows around an estimated circadian nadir, not medical prescriptions.
OneFreePlace · Tool #127
Plan the clock shift—not just the flight—with a transparent jet-lag schedule.
Use real IANA time zones and your normal sleep pattern to estimate the circadian shift, pre-adjust sleep before departure, find destination-aligned sleep opportunities in flight, map light-seeking and light-avoidance windows, compare adaptation vs quick-turnaround strategies, and check whether an important event lands inside your estimated body-night window.
✓ DST-aware IANA zones✓ Pre-travel shifting
✓ Light seek / avoid windows✓ Flight sleep analysis
✓ ICS plan export
Jet Lag Planner
DST-aware · circadian shift · light timing · quick turnaround
Trip setup
Tell the planner what your body clock is moving between.
Departure clock time occurs twice because the clock moves backward.
Arrival clock time occurs twice because the clock moves backward.
Normal sleep & destination targetUsed to estimate circadian phase and body-night timing.
StrategyThe plan stays explicit about what it is optimizing.
Optional important eventChecks whether it overlaps your projected body-sleep window.
Example: a presentation, race, exam or first-day meeting. This is a body-clock overlap check, not a prediction of individual performance.
Circadian shift
Calculating—
clock shift
Complete the trip setup.
Flight duration—timezone-aware elapsed time
Offset at arrival—destination vs home UTC offset
Adaptation estimate—population-average planning estimate
Pre-shift achieved—before departure
Arrival body wake—destination local clock estimate
Arrival body nadir—approx. 3h before body wake
Strategy note
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Important-event check
Add an event if you want a body-clock overlap check.
Best sleep opportunity in flight
The planner intersects your actual flight interval with your target destination sleep window.
——
—Home-clock sleep translated into destination local time.
Arrival-day body-clock map
Blue = desired destination sleep. Purple = estimated biological sleep window on arrival. Yellow = seek bright light. Orange = reduce/avoid bright light. Times are destination local.
Strategy comparison
Adapt toward destination——
Quick turnaround——
Advance pace~1 h/dayCDC Yellow Book population-average adaptation rate for eastward / advance shifts.
Delay pace~1.5 h/dayCDC Yellow Book population-average adaptation rate for westward / delay shifts.
Evidence & safety notes
Sleep timingCDC recommends shifting sleep toward destination time for a few days before travel when possible and timing activities to destination time during travel.
LightMorning light after the circadian nadir tends to advance the clock; evening light before the nadir tends to delay it. Mistimed light can shift the clock the wrong way.
Naps & caffeineShort naps around 20–30 minutes can support alertness. The plan uses a conservative caffeine cutoff 6 hours before target sleep; individual sensitivity varies.
Melatonin / medicationsThis tool does not generate dosing or medication instructions. Melatonin timing is phase-sensitive and can interact with medications; discuss it with a qualified clinician or pharmacist if relevant.
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This is a planning aid, not medical care.Jet lag varies substantially between people. The schedule uses a simplified circadian model and current browser time-zone data. If sleep disruption is severe, persistent, or safety-critical—or if you are considering medication—seek individualized medical advice.