London to New York delays your body clock by about five hours – a westward trip, the easier direction, and a modest shift. Most travellers feel only mildly jet-lagged for three to four days. Staying up to a normal New York bedtime and getting afternoon daylight is usually all it takes to reset.
London to New York at a glance
| Time difference | New York is 5 hours behind London for most of the year |
|---|---|
| Direction | Westward – your clock delays (the easier direction) |
| Time zones crossed | About 5 |
| Jet lag estimate | Roughly 4 out of 10 (moderate) |
| Body clock on arrival | You land in the afternoon; your body reads early evening |
| Adaptation | Around 3-4 days |
| Flight time | About 8 hours (westbound) |
These figures are transparent estimates, not clinically validated. The exact time difference depends on the date; the calculator resolves it for your trip.
Time difference and direction
New York is five hours behind London through most of the year, both cities keeping broadly aligned daylight-saving dates. You are travelling west, so your clock delays – the gentle direction – and five hours is a comfortable shift. This is one of the easier transatlantic trips, and it scores lower than the eastbound return; compare it directly with New York to London.
Jet lag estimate and body clock
Expect a mild-to-moderate jet lag, around four out of ten. Flights usually leave London in the late morning and land in New York in the afternoon, but your body is already reading early evening, so you may fade after dinner and wake early the next day. Both effects are minor and short-lived on a five-hour westward shift.
Adaptation: how long it lasts
Most people feel normal within three to four days, and a short trip may barely register. Westward five-hour shifts are near the easy end of long-haul jet lag. See how long does jet lag last for the general rule.
Before the flight
Little preparation is needed. If you want an edge, go to bed an hour later for a night or two before departure. Above all, arrive rested – travel fatigue, not the time shift, is often the bigger drag on such a short hop.
During the flight
This is a daytime westbound flight, so stay awake. Set your watch to New York time on boarding, keep hydrated, avoid alcohol, and keep any nap short so it does not blunt your first local night.
After arrival
Stay up to a normal New York bedtime, helped by late-afternoon daylight, which nudges your clock later. Avoid very early bright light on the first mornings so you do not pull back toward London time. Keep meals on local time. For the exact light windows, use the light exposure planner.
Calculate your personal plan
Get a day-by-day schedule tailored to your exact departure time and sleep habits, with this route already filled in.
Sources
- U.S. Centers for Disease Control and Prevention – CDC Yellow Book, “Jet Lag” chapter – direction asymmetry and timed light.
- NHS – “Jet lag” (nhs.uk/conditions/jet-lag/), last reviewed 31 May 2023.
- Sleep Foundation – “Jet Lag” educational overview.
- IANA Time Zone Database – offsets for Europe/London and America/New_York.