Jet lag calculatorFind out when to sleep on your flight.
Enter your flight to get the time difference, your sleep window on board and what to do on arrival. Summer and winter time are taken into account for your travel date.
Westward: your body clock has to move later. This is usually the easier direction. Without a strategy, allow about 4 days for your body clock to fully adjust: on average it shifts by about 1 hour per day eastward and 1.5 hours per day westward (CDC).
Your in-flight plan · Paris → New York
All times are shown in destination time.
Boarding: switch to New York time
It is 04:30 in New York. Set your watch and live on destination time from now on.
Stay awake during the flight
It is daytime in New York during your flight. Keep the light on, walk the aisle and drink water. If you are exhausted, limit yourself to naps of 20–30 minutes.
Landing at 12:55 local time
Stay active until local bedtime (10–11 pm) and spend time outdoors later in the day.
First days at destination
- Light: avoid bright light early in the morning and get daylight in the late afternoon and early evening. This is what helps your body clock move later.
- Naps: if you need one during the day at destination, keep it to 20 or 30 minutes so you can still sleep at night.
- Caffeine: no coffee or tea in the 6 hours before you plan to sleep.
- Hydration: drink water regularly and go easy on alcohol, which disrupts sleep and makes symptoms worse.
That is the general rule. The EOLE app adapts it to you.
The app builds your plan from your chronotype and your itinerary, then guides you through the flight: when to seek or avoid light, guided breathing and movement, hydration reminders, and an arrival plan for your first days. It works offline, in airplane mode. Free to download on iOS and Android.
General guidance based on chronobiology, not medical advice. If you have a health condition, are pregnant or take medication, ask a health professional.
How the calculator works
It places your sleep window in the destination night (11 pm–6 am local time), after the meal service and up to 45 minutes before landing. If it is daytime at your destination for the whole flight, it tells you to stay awake.
Recovery times use the average rates published by the CDC: the body clock adjusts by about 1 hour per day after an eastward flight and 1.5 hours per day after a westward one (CDC Yellow Book 2026). These are averages, and recovery varies between people.
Go further with the app
The calculator gives everyone the same rule. The EOLE app builds a protocol around you.
Your chronotype, the purpose of your trip and your exact itinerary: EOLE uses them to guide you step by step on when to seek or avoid light, breathe, move and drink, then helps you through your first days on arrival. Designed with a medical advisor and performance experts, including a former staff member of a French Olympic team.
- Personalized to your chronotype
- Step-by-step guidance in flight
- Works offline, in airplane mode
- Arrival plan for your first days
Free to download on iOS and Android.
Popular routes
From Paris
- Paris → New York
- Paris → Boston
- Paris → Washington, D.C.
- Paris → Montreal
- Paris → Toronto
- Paris → Chicago
- Paris → Miami
- Paris → Houston
- Paris → Los Angeles
- Paris → San Francisco
- Paris → Mexico City
- Paris → Cancún
- Paris → Pointe-à-Pitre (Guadeloupe)
- Paris → Fort-de-France (Martinique)
- Paris → Cayenne (French Guiana)
- Paris → Bogotá
- Paris → São Paulo
- Paris → Rio de Janeiro
- Paris → Buenos Aires
- Paris → Dubai
- Paris → Doha
- Paris → Riyadh
- Paris → Mumbai
- Paris → Delhi
- Paris → Bengaluru
- Paris → Bangkok
- Paris → Ho Chi Minh City
- Paris → Singapore
- Paris → Hong Kong
- Paris → Shanghai
- Paris → Beijing
- Paris → Seoul
- Paris → Tokyo
- Paris → Réunion (Saint-Denis)
- Paris → Mauritius
- Paris → Sydney
- Paris → Papeete (Tahiti)
To Paris
- New York → Paris
- Boston → Paris
- Washington, D.C. → Paris
- Montreal → Paris
- Toronto → Paris
- Chicago → Paris
- Miami → Paris
- Houston → Paris
- Los Angeles → Paris
- San Francisco → Paris
- Mexico City → Paris
- Cancún → Paris
- Pointe-à-Pitre (Guadeloupe) → Paris
- Fort-de-France (Martinique) → Paris
- Cayenne (French Guiana) → Paris
- Bogotá → Paris
- São Paulo → Paris
- Rio de Janeiro → Paris
- Buenos Aires → Paris
- Dubai → Paris
- Doha → Paris
- Riyadh → Paris
- Mumbai → Paris
- Delhi → Paris
- Bengaluru → Paris
- Bangkok → Paris
- Ho Chi Minh City → Paris
- Singapore → Paris
- Hong Kong → Paris
- Shanghai → Paris
- Beijing → Paris
- Seoul → Paris
- Tokyo → Paris
- Réunion (Saint-Denis) → Paris
- Mauritius → Paris
- Sydney → Paris
- Papeete (Tahiti) → Paris