Jet lag from Paris to Hong Kong: what to expect
Fly Paris to Hong Kong and local time runs 7 hours ahead of your body. Land at 07:30 and your body still thinks it's 00:30 in Paris. That's the middle of your body's night. At 23:00 in Hong Kong, it's 16:00 for you.
That's an eastward shift: your clock has to move earlier, against its natural drift S1. It's why the first nights after flying east bring trouble falling asleep at local bedtime, and a groggy late morning S1.
How long does jet lag last from Paris to Hong Kong?
Unaided, eastward shifts settle at around a day per time zone: about 7 days for this one. S6 S7
This plan targets 5 days.
That's what the plan aims at, not a promise — bodies vary.
For this trip that's 2 days sooner than the unaided estimate, on the effort level that fits around a working day.
On night one the plan's bedtime is 01:00, late by Hong Kong's clock. It holds there for 4 nights, then moves to 23:00 by night 6.
Studies of aircrew point the same way: after large shifts, westward adaptation runs roughly 50% faster than eastward S6 S8. This trip is on the slow side of that.
What does the plan say for a typical Paris to Hong Kong flight?
- Departs
- 12:20 Paris time
- Lands
- 07:30 Hong Kong time +1 day
- In the air
- about 12h 10m (estimate)
- Light, landing day
- 12:25–13:25 Get outside into bright light
- Keep it dim, landing day
- 22:00–00:00 Avoid bright light before bed
- Last caffeine, landing day
- 17:00
- Nap after landing
- 09:00 Nap when you can lie down, up to 90 min
- First night's sleep
- 01:00–09:00
Eastbound long-hauls tend to land in the morning, so this example lands in Hong Kong at 07:30, leaving Paris at 12:20 the day before, after about 12h 10m in the air.
The flight time is our estimate for a nonstop from the distance, and the trip is set in January. It's the default traveler from the calculator: usually asleep 23:00 to 07:00, no melatonin, Real Life effort.
In July the gap is 6 hours, not 7, because Paris moves its clocks for summer and Hong Kong doesn't.
The plan puts about 3 hours of sleep on board, from 04:25 to 07:00 Hong Kong time, ending half an hour before you land. What's left of that night becomes a nap on the ground at 09:00: "Nap when you can lie down, up to 90 min".
The day before you fly, the plan starts with light at 07:00–08:00 Paris time. In January that's before sunrise in Paris (about 08:35), so it means bright indoor light.
In January the sun is up in Hong Kong from about 07:05 to 18:04, so the 12:25 light step on landing day is daylight. Outside is the easy way to get it.
What helps after flying east to Hong Kong?
Going east, you want light after your body's low point and darkness before it S1. In the first days after a big shift that often means sunglasses in the morning and the early afternoon outside. Why flying east is harder goes through the mechanism.
Melatonin has its best trial results on eastward flights across five or more time zones S5. It's a timing signal, not a sleeping pill: melatonin for jet lag covers when to take it. Check with your doctor first.
And the flight home from Hong Kong?
Hong Kong to Paris is the same 7 hours the other way, westward. It's the easier direction: about 5 days unaided, and the plan targets 4. Plan the flight home from Hong Kong with your own times.
More routes from Paris
Sources
Numbered from the site-wide source registry — every Delagged page uses the same numbering.
- S1 Roach GD, Sargent C. Interventions to Minimize Jet Lag After Westward and Eastward Flight. Frontiers in Physiology, 2019;10:927. doi:10.3389/fphys.2019.00927
- S5 Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database of Systematic Reviews, 2002. doi:10.1002/14651858.CD001520
- S6 Waterhouse J, Reilly T, Atkinson G, Edwards B. Jet lag: trends and coping strategies. The Lancet, 2007;369:1117–29. doi:10.1016/S0140-6736(07)60529-7
- S7 Eastman CI, Burgess HJ. How to travel the world without jet lag. Sleep Medicine Clinics, 2009;4:241–55. doi:10.1016/j.jsmc.2009.02.006
- S8 Samel A, et al. Aircrew adaptation after transmeridian flights, 1995. As cited in Waterhouse et al., The Lancet 2007 (S6). Full text Cited via S6.