Helpful Toolbox

Jet Lag Planner

Enter how many time zones you will cross, which direction you are flying, and how many nights you have to prepare. The planner builds a night-by-night bedtime schedule that shifts your sleep about one hour per day and estimates how long full adjustment will take after you land. Everything runs in your browser — nothing is uploaded.

📖 How it works & FAQ

Beat jet lag before you board

Jet lag happens because your internal clock is still running on home time when you land. The classic rule of thumb: your body naturally adjusts about one time zone per day, and you can pre-shift roughly one hour of sleep per night before departure. This planner turns those two rules into a concrete schedule. Flying east compresses your day, so bedtime needs to move earlier; flying west stretches it, so bedtime moves later. Every night you shift in advance is one fewer groggy day at your destination.

All of the rates are editable. If you know you adapt slowly, raise the adjustment rate above one day per zone; if you can only tolerate a 30-minute change per night, lower the shift per night and add more prep days. The plan recalculates instantly as you type, and nothing leaves your browser.

How to use it

  1. Enter the number of time zones you will cross (the hour difference between home and destination).
  2. Pick your direction of travel — east means earlier bedtimes, west means later.
  3. Set your usual bedtime and how many prep nights you have before the flight.
  4. Adjust the shift-per-night and days-per-zone rates if the defaults do not fit you.
  5. Read the night-by-night table: each row is a target bedtime in home time, ending at your destination rhythm.

These are educational estimates only, not medical or professional advice; individual sleep responses and schedules vary.

FAQ

Why is eastward travel harder?
Most people have an internal clock slightly longer than 24 hours, so delaying sleep (westward) is easier than advancing it (eastward). Give yourself extra prep nights or a gentler shift when flying east.
What if I cannot shift a full hour per night?
Lower the shift-per-night value to 0.5 or 0.25 hours. The planner caps the total shift at your time zone difference, and any hours you cannot pre-shift roll into the after-arrival estimate.
Do light and meals matter too?
Yes. Bright light in the morning helps you advance for eastward trips, and evening light helps you delay for westward ones. Moving meal times along with bedtime reinforces the shift.
Is my data stored anywhere?
No. The calculation runs entirely in your browser, and nothing is saved or transmitted.