Jet lag from London to Los Angeles: what to expect
Fly London to Los Angeles and local time runs 8 hours behind your body. Land at 14:10 and your body still thinks it's 22:10 in London. That's the middle of your body's night. At 23:00 in Los Angeles, it's 07:00 for you.
That's a westward shift: your clock has to move later, which is the way it drifts on its own S1. Expect to be sleepy early in the evening for the first few days, and awake before your alarm S1.
How long does jet lag last from London to Los Angeles?
Unaided, westward shifts settle somewhat faster than a day per time zone: about 6 days for this one. S6 S7
This plan targets 4 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 21:00, early by Los Angeles's clock. It holds there for 4 nights, then moves to 23:00 by night 5.
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 quick side of that.
What does the plan say for a typical London to Los Angeles flight?
- Departs
- 11:00 London time
- Lands
- 14:10 Los Angeles time
- In the air
- about 11h 10m (estimate)
- Light, landing day
- 18:40–19:40 Seek bright light (delay shift)
- Last caffeine, landing day
- 13:00 on the plane
- Last caffeine, first full day
- 13:00
- First night's sleep
- 21:00–05:30
Westbound flights often go by day, so this example leaves London at 11:00 and lands in Los Angeles at 14:10 in the afternoon, after about 11h 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.
On board, the plan keeps you awake apart from a short nap at 05:00 Los Angeles time, saving the real sleep for the night in Los Angeles.
The day before you fly, the plan keeps your morning dim, 07:00–09:00 London time, and the sun is up in London by about 07:57 in January, so plan on sunglasses for the commute.
On landing day your last coffee comes on the plane, at 13:00 Los Angeles time, and the plan has none between landing and your first night's sleep. From 05:30, when you wake from that first sleep, it allows it again, until 13:00.
January days are short in Los Angeles: about 10 hours of daylight. In January the sun sets in Los Angeles at about 17:10, so the 18:40 light step on landing day comes after dark. It has to be bright indoor light.
What helps after flying west to Los Angeles?
Going west, you want light before your body's low point, which usually means bright light in the evening and staying up a little later S1. Bright light first thing in the morning works against you. East vs west explains why this direction is the easier one.
On a shift this size, starting before you fly pays off. The Frontiers review describes moving bedtime 30 to 60 minutes later each day for 3 to 4 days before a westward trip S1. The plan's version is one night: bed at 00:00 the night before you fly, an hour later than usual.
And the flight home from Los Angeles?
Los Angeles to London is the same 8 hours the other way, eastward. It's the harder direction: about 8 days unaided, and the plan targets 6. Jet lag from Los Angeles to London has the details.
More routes from London
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
- 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.