Beat Jet Lag: Sleep Calculator for Travelers

How Jet Lag Affects Sleep

When crossing 3+ time zones, your circadian rhythm (body clock) falls out of sync with local time. Symptoms include insomnia, daytime drowsiness, poor concentration, and digestive issues. It takes roughly 1 day per time zone crossed to fully adjust.

Pre-Flight Sleep Adjustment

Start adjusting 2–3 days before departure: flying east — shift bedtime and wake time 1 hour earlier each day. Flying west — shift 1 hour later. Use a sleep calculator to plan each day's sleep schedule so your body adapts ahead of time.

In-Flight Sleep Strategy

Decide whether to sleep or stay awake on the plane based on your arrival time. If you arrive at night, sleep on the plane. If arriving during the day, stay awake. Use the sleep calculator to figure out how many 90-minute cycles to aim for during the flight.

Post-Arrival Recovery

Immediately live on local time after arrival. Key tip: get lots of sunlight during the day (light is the strongest circadian regulator) and avoid blue light at night. Use the sleep calculator to set your new bedtime and wake up at the right point in your sleep cycle.

Practical Tips

• Short jet lag (1–3 hours) — usually resolves in 1–2 days naturally
• Medium jet lag (4–6 hours) — adjust 2 days before, recover in 3–4 days
• Large jet lag (7+ hours) — adjust 3 days before, consider melatonin
• Limit naps to 20 minutes — longer naps disrupt nighttime sleep
• Stay hydrated — dehydration worsens jet lag symptoms

FAQ

How long does jet lag take to recover?

About 1 day per time zone. 5 zones ≈ 5 days.

How to adjust before flying?

Shift sleep 1–2 hours earlier (east) or later (west) 2–3 days before.

How to adapt after arrival?

Sunlight during day, avoid blue light at night, live on local time.