Which jet lag tips do the sources give?

Get light at the right time for your direction: afternoon and evening after flying west, morning after flying east (later in the day for the first days after a big jump). Start shifting your sleep a few days before, sleep on the plane if it is night at your destination, and keep naps short.

Are there natural ways to adjust to a new time zone?

The tools you control are about timing: daylight at the right time of day, a sleep schedule moved toward the new time zone and short naps. Sunlight is the strongest time cue for the body clock (Roach & Sargent, 2019). For medicines or supplements, ask a doctor or pharmacist.

Should I sleep on the plane?

Yes, if it is night at your destination. Plan sleep, meals and light around destination time (NHS, 2023; CDC Yellow Book, 2025). Too much alcohol or caffeine can make jet lag worse (NHS, 2023).

Guide · Travel

Jet lag and light: timing daylight after a long flight

After a long flight across time zones, your body clock is still running on home time and needs several days to catch up. Light is one of the main signals for moving it (Roach & Sargent, 2019). It only helps at the right time of day, though, and the right time depends on which way you flew.

LightOtter editorial team · reviewed against the sources below · 12 October 2026 · updated 13 October 2026 · Who is behind it

The short answer

When does daylight help with jet lag?

Light at the right time moves your body clock toward local time (Roach & Sargent, 2019). After flying west, get daylight in the afternoon and evening. After flying east, get morning light, or light later in the day after big jumps. Moving your sleep 30 to 60 minutes a day before the trip covers part of the shift.

How long does jet lag last?

It usually gets better within a few days (NHS, 2023). As a rough average, the body clock shifts about 1.5 hours a day after flying west and 1 hour a day after flying east (CDC Yellow Book, 2025), so six time zones east can take close to a week.

Work out your days and light times with the jet lag calculator.

Jet lag symptoms after a long flight

Jet lag is when your normal sleep pattern is disturbed after a long flight. The NHS names these main symptoms and adds that jet lag can sometimes also cause indigestion, feeling sick, constipation and changes in appetite (NHS, 2023):

difficulty sleeping at bedtime and waking up in the morning
tiredness and exhaustion
difficulty staying awake during the day
poor sleep quality
concentration and memory problems

Why is jet lag worse going east?

Your body clock does not switch to local time when you land. For a while it stays on home time, and that gap is what causes jet lag (Roach & Sargent, 2019). The night of sleep you lose on the flight is part of it, but you can mostly make that up in a day. The gap between your clock and local time lasts longer (Eastman & Burgess, 2009).

Flying west, your clock has to run later. Flying east, it has to run earlier, and that is harder for most people because the body clock naturally runs a little longer than 24 hours. As a rough average, it catches up about 1.5 hours a day after flying west and about 1 hour a day after flying east (CDC Yellow Book, 2025).

Jet lag without a flight: social jet lag from late weekends.

After flying east: light at the right time of day

Light in the hours after your body’s nightly low point moves the clock earlier. Light in the hours before it moves the clock later (Roach & Sargent, 2019). Right after a flight east, that low point is still on home time. If you usually sleep from 11 pm to 7 am, it falls around 7 am local time after a flight three hours east, so ordinary morning light helps (Roach & Sargent, 2019).

After a bigger jump east, the low point lands later in the local day: around 10 am after six hours, around 1 pm after nine hours (Roach & Sargent, 2019). For a flight eight hours east, such as Los Angeles to London, Roach and Sargent suggest avoiding sunlight before midday and getting as much as you can in the three to six hours after it. Soaking up daylight at any time of day after a long flight east can send mixed signals and slow you down (Roach & Sargent, 2019).

Once your body clock has mostly caught up, the usual pattern applies: morning light moves it earlier, evening light moves it later (CDC Yellow Book, 2025). Never look directly at the sun.

Sunrise and day length by city and month.

After flying west: light later in the day

West is the easier direction. Here, getting plenty of daylight generally works well, because afternoon and evening light moves your clock later, which is what you need (Roach & Sargent, 2019; CDC Yellow Book, 2025).

Try to stay awake until a normal local bedtime, so you sleep better at night. If you need a nap, keep it short. The CDC mentions 20 to 30 minutes; longer naps can get in the way of sleep at night (CDC Yellow Book, 2025).

One hour at home: the 4-day plan for the clock change.

Start a few days before you fly

You can cover part of the shift before you leave. In the 3 to 4 days before a trip east, go to bed and get up 30 to 60 minutes earlier each day, get bright light in the morning and keep evenings dim. Before a trip west, do the opposite: later bedtimes, more evening light, less morning light (Roach & Sargent, 2019). The CDC describes a similar step of one hour a day over two to three days, and suggests picking a flight that lands when you can get light at a useful time (CDC Yellow Book, 2025).

In one study, people moved their sleep one hour earlier a day for three days. With bright morning light their body clock shifted about 1.5 to 2 hours; in dim indoor light it shifted about 0.6 hours (Burgess et al., 2003). Daylight outdoors is almost always brighter than the lamps used in such studies (Eastman & Burgess, 2009). The same researchers write that even one or two days of shifting help, and advise moving earlier by no more than an hour a day.

The same steps at home: the 7-day plan to reset your circadian rhythm.

Should you switch to local time on a short trip?

On a trip of two to three days, you could keep your home times for sleeping and eating, so you don’t have to switch back right after (NHS, 2023). The CDC also lists keeping home sleep hours on short trips (CDC Yellow Book, 2025).

For a longer stay, switch to local sleep times as soon as you can and set an alarm so you don’t oversleep in the morning (NHS, 2023).

What this is not

This guide covers the timing of light and sleep, not medicines or supplements. Light plans for jet lag rest mainly on lab studies. Field studies with real travelers are few, and their results are mixed (Roach & Sargent, 2019). LightOtter’s minutes are a daily rule of thumb for morning light, estimated from clouds and the sun’s position, not a personal jet lag plan. If you stay tired for a long time after a trip, talk to a doctor.