Should I sleep on the London to New York flight?

    Mostly no — London → New York delays your clock 5 hours westward, so staying awake in the air and going to bed at local New York time works better than arriving rested and wide awake at 03:00.

    Flight time
    6h 51m to 7h 50m
    5,540 km
    Body-clock shift
    5 hours
    westward
    To adjust
    4 days
    moderate jet lag

    Why, for this route

    • Set your watch to New York time at the gate and treat the cabin as destination time.
    • When it is 08:00 in New York, your body clock reads 13:00 — that gap is what the flight can start closing.
    • Keep the cabin light on, move every couple of hours, and save caffeine for the first half of the flight.
    • Expect about 4 days to adjust after landing (moderate jet lag).

    Day 1 in New York

    • 17:00–19:00Seek bright light
    • 16:00Last caffeine
    • 00:00–08:00Target sleep window

    Get this plan for your own dates

    The calculator opens with LHR → JFK already filled in.

    Build my LHR → JFK plan

    Evidence-based recommendations

    Each recommendation below is graded by how strongly published research supports it, with the source it comes from. Optimal timing depends on your travel direction, the number of time zones crossed and your own circadian phase, so treat the schedule as a starting point.

    • Seek evening light

      Strong

      Bright light in the local evening helps delay your body clock when travelling west.

      CDC Yellow Book 2026
    • Limit light in the early morning

      Strong

      Early light can advance your clock and work against a westward shift during the first days.

      NIH — Circadian rhythms
    • Shift bedtime later before departure

      Moderate

      Moving sleep and wake times 30-60 minutes later for a few nights gives your clock a head start on a westward trip.

      CDC Yellow Book 2026
    • Live on destination time on arrival

      Moderate

      Sleeping, eating and being active on local time gives your body consistent cues about the new day.

      CDC Yellow Book 2026
    • Consider timed melatonin

      Moderate

      Low-dose melatonin near the local bedtime can help with sleep timing after crossing several zones; timing matters more than dose.

      Cochrane review — Melatonin for jet lag
    • Use caffeine early, not late

      Practical advice

      Caffeine can help you stay awake during local daytime, but late doses tend to delay sleep onset.

      CDC Yellow Book 2026
    • Protect sleep around the flight

      Practical advice

      Arriving without a large sleep debt makes the first days easier, even when few time zones are involved.

      CDC Yellow Book 2026

    How we grade evidence

    Strong
    Consistently supported by controlled circadian research and current public-health guidance.
    Moderate
    Supported by research, but effect size and best timing vary between individuals and studies.
    Practical advice
    Sensible travel habits with limited direct evidence for shifting the body clock.

    This is general travel information, not medical advice. Talk to a clinician before using melatonin or sleep medication, especially if you are pregnant, take other medication or have a sleep disorder.

    Ready to plan your next trip?

    Get flight times, time zone comparisons, and a personalized jet lag plan in seconds.

    Start Planning