Jet Lag Planner

Guide: planning around jet lag

What it does

Jet lag happens because your internal body clock is still on home time while the sun, meals, and sleep are on destination time. This planner estimates how many days you'll need to adjust based on the number of time zones you cross and the direction you fly, then builds a day-by-day bedtime shift schedule and tells you when to seek light and when to avoid it — the single most powerful lever for resetting your clock faster. Free, private, no signup.

How to use it

1. Enter the number of time zones between home and your destination (the hour difference).
2. Pick your direction — eastward (clock advances, harder) or westward (clock delays, easier).
3. Enter your usual bedtime and whether you want to start adjusting before you fly.
4. Read the estimated adjustment time, the light-timing advice, and follow the bedtime schedule day by day.

Worked example

A 6-zone eastward trip (say New York → Rome), usual bedtime 11pm, starting 2 days before you fly:

1. Eastward adjusts at about 1 zone per day → estimated ~6 days to fully sync.
2. Going east means advancing your clock, so each step moves bedtime earlier by ~1 hour.
3. Day −2 (pre-flight): bedtime 10pm. Day −1: 9pm. Then continue shifting earlier after you land.
4. Light plan: seek bright morning light at the destination, avoid bright light late evening — this pulls your clock earlier to match local time.

Fly the same route westward (Rome → New York) and the model adjusts faster (about 1.5 zones/day ≈ 4 days), shifts bedtime later, and flips the light advice: seek evening light, avoid early-morning light.

How the estimate is built

days to adjust:
  eastward (advance, harder)  = zones / 1.0   (about 1 zone per day)
  westward (delay, easier)    = zones / 1.5   (about 1.5 zones per day)
  rounded up; capped near 12 (clock can't shift faster)

bedtime shift per day = 1 hour
  eastward  -> bedtime moves EARLIER each day
  westward  -> bedtime moves LATER each day

light timing:
  eastward  -> seek MORNING light, avoid LATE-EVENING light
  westward  -> seek EVENING light, avoid EARLY-MORNING light

These are widely used chronobiology rules of thumb, not a clinical protocol. Individual response varies, and very large shifts (8+ zones) sometimes adjust by going the "other way" round the clock.

Tips to beat jet lag faster

• Light is the master switch. Get it at the right time for your direction and avoid it at the wrong time — sunglasses help you "avoid" light on demand.
• Get on local time immediately. Eat and sleep on the destination's schedule the moment you land, even if you're tired.
• Pre-adjust a little. Shifting bedtime 30–60 min/day before you go shortens the gap your body has to close.
• Hydrate, limit alcohol, and time caffeine for the morning, not the afternoon, at your destination.
• Fully client-side — nothing leaves your browser.

Common mistakes this tool prevents

• Assuming east and west jet lag take the same time — eastward is harder.
• Getting light at the wrong time and accidentally pushing your clock the wrong way.
• Trying to "power through" on home time instead of switching to local sleep and meals.
• Leaving all the adjustment until after you land instead of starting a day or two early.

How to embed this tool on your website

No account, no coding. Copy the embed code and paste it where you want it to appear:

<iframe src="https://snaptoolsuite.com/jet-lag-planner/?embed=1"
  style="width:100%;max-width:560px;height:1200px;border:0;"
  title="Jet Lag Planner" loading="lazy"></iframe>
<p>Free <a href="https://snaptoolsuite.com/jet-lag-planner/">Jet Lag Planner</a> by Snap Tool Suite</p>

See it live: view a real embed example →

Frequently asked questions

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