According to Timeshifter and by applying the one-day-per-zone rule of thumb, a flight from New York to London crosses five time zones and typically causes jet lag for about five days. A few travel tweaks made before and after the flight can shorten it.
Important Note
TravelTweaks Hotels is a purely informational platform. This article is general travel information, not medical advice. If you take medication that affects sleep or have a sleep disorder, speak to a clinician before using melatonin or changing your schedule.
Why Direction Changes Everything
Jet lag happens when your body clock stays in the time zone you left. The CDC Yellow Book says crossing at least two time zones may cause it, and the Sleep Foundation puts the threshold at three or more.
Direction matters. Sleep Foundation found that Eastward travel is harder for about 75% of people, though 25% find westward harder. Recovery estimates vary by source:
- One day per zone eastward and half a day per zone westward (Botonis et al., Experimental Physiology, via Manta Sleep)
- 1 to 1.5 days per zone overall (American Academy of Sleep Medicine via Sleep Reset)
Treat these as ranges, because individual recovery differs. The travel tweaks which matter most depend on the direction you fly.
Shift Your Sleep Before You Fly
This is the simplest of the travel tweaks because it starts at home and costs nothing. In the 3 to 5 days before departure, move your sleep and wake times toward the destination.
Sleep Reset advises that go 30 to 60 minutes earlier per night for eastward trips and 30 to 60 minutes later for westward trips. Start early, because travel tweaks like this work best when the shift is gradual.
Pick the Flight and Day First
According to the Sleep Foundation, Total travel time, including stopovers, is one factor in how bad jet lag gets. A cheap itinerary with a long layover can cost you a day of recovery. Check the fare and the journey length together. Our guide to the best times of year to find cheap travel deals covers the fare side.
Use Light on Purpose
Sleep Reset says Timed light exposure is the most effective non-drug tool for jet lag. The direction rules:
- Eastward: Seek morning light and avoid bright light in the evening
- Westward: Seek evening light and avoid bright light in the early morning
(Sleep Reset; Timeshifter)
Wrong-time light can make things worse. The Sleep Foundation warns that light and melatonin at the wrong time of day can further desynchronize your rhythm.
Live on Destination Time Early
According to a guide by Hotels By Day Travel Recovery, Set your watch to destination time when you board. Then match meals, caffeine, exercise and sleep to the new time zone. This is sometimes called chrono-modulation.
Your First 48 Hours
The first two days set the pattern. Plan an easy day one with outdoor time at the right hour, a destination-time dinner and an early night. Avoid a packed itinerary on arrival.
We cover this planning problem in what the map guide TTweakMaps covers for honeymoon destinations, where a couple’s trip was rescued by cancelling the first two days.
Staying indoors all day is among the most common recovery mistakes. (Hotels By Day 2026)
What About Melatonin?
A Cochrane systematic review via Sleep reset found melatonin effective for jet lag when crossing five or more time zones. Take it at your destination’s local bedtime, not at your home time zone’s sleep time.
Sleep Foundation claims that Like light, it can shift the clock earlier or later, so wrong timing can backfire.
Conclusion
Jet lag cannot be avoided entirely on a long-haul flight, but the right travel tweaks can shorten it. Shift your sleep before you fly, choose a sensible flight, get light at the right hour and give yourself an easy first two days.
None of these travel tweaks cost money, and all of them start before you board.