Question 1

What is jet lag and why does it happen?

Accepted Answer

Jet lag is a temporary sleep disorder that occurs when you travel across multiple time zones. Your internal circadian rhythm (body clock) becomes out of sync with the local time at your destination, causing fatigue, difficulty sleeping, poor concentration, and digestive issues.

Question 2

How long does jet lag typically last?

Accepted Answer

Without intervention, jet lag typically lasts about one day per time zone crossed. For example, traveling from New York to London (5 time zones) might cause jet lag for 5 days. However, with proper pre-adaptation and light exposure timing, recovery time can be cut in half.

Question 3

Why is eastward travel harder than westward?

Accepted Answer

Most people's natural circadian rhythm is slightly longer than 24 hours. Westward travel (phase delay) aligns with this natural tendency of staying up late, making it easier. Eastward travel (phase advance) requires going to bed earlier, which fights against your body's natural inclination. The adjustment rate is also slower: about 1 hour per day eastward vs. 1.5 hours per day westward.

Question 4

Does this calculator really work?

Accepted Answer

The calculator is based on established circadian rhythm research and the same principles used by NASA and elite athletes. Effectiveness varies by individual based on how strictly you follow the schedule, your ability to control light exposure, individual circadian rhythm sensitivity, and lifestyle factors.

Question 5

What counts as bright light for jet lag adjustment?

Accepted Answer

Best option is natural outdoor sunlight for 30-60 minutes. Indoor alternatives include a 10,000 lux light therapy box for 30 minutes or bright indoor lighting (all lights on, near windows) for 2-4 hours. Regular indoor lighting and phone screens are not sufficient.

Question 6

Should I take melatonin for jet lag?

Accepted Answer

Melatonin can be helpful for eastward travel (phase advance) when taken at the right time, typically 30-60 minutes before your target bedtime. It is generally less useful for westward travel. Always consult a doctor before taking melatonin, especially if you have autoimmune disorders, are pregnant, or take other medications.

Question 7

What if I can't follow the schedule exactly?

Accepted Answer

Do your best with ±1 hour flexibility on timing. The most important elements are getting the light exposure direction right (SEEK vs AVOID) and shifting your sleep in the right direction. Even partial adherence helps. If you miss a day, continue with the plan from where you are.

Question 8

How far in advance should I start using the plan?

Accepted Answer

Ideally, start 3-5 days before departure. The calculator typically recommends starting 3 days early, which allows you to pre-shift your rhythm by 2-3 hours. Even 1-2 days of pre-adjustment helps, and following the post-arrival plan is still beneficial without pre-flight adjustment.

Frequently Asked Questions

General Questions

Using the Calculator

Light Exposure

Melatonin

Special Situations

Troubleshooting

Still Have Questions?

Frequently Asked Questions

General Questions

What is jet lag and why does it happen?

How long does jet lag typically last?

Why is eastward travel harder than westward?

Does this calculator really work?

Using the Calculator

How far in advance should I start using the plan?

What if I can't follow the schedule exactly?

What about short trips (less than 3 days)?

Can I use this for trips with multiple destinations?

Light Exposure

What counts as "bright light"?

Do I really need to avoid light in the middle of the night?

Does light through windows count?

Should I use blue-light blocking glasses?

Melatonin

Should I take melatonin?

What dose of melatonin should I take?

Special Situations

What if I already have jet lag?

I work night shifts. Can I use this calculator?

Does this work for children or elderly travelers?

Troubleshooting

I followed the plan but still feel tired. Why?

I can't fall asleep at the recommended time. What should I do?

I feel worse after following the plan. Is that normal?

Still Have Questions?