Everyone has an internal clock. It is linked to the light you take in through your eyes from day to day.

When you travel by airplane across time zones quickly, there is a dramatic change in when and how much light you are exposed to. You arrive in a new time zone and your body is still wired to the sun patterns from your home location. You get light when your body is used to darkness, and vice versa. And that disrupts your internal clock and causes jet lag.

If you are traveling east, you will likely have difficulty falling asleep at night. And if you are traveling west, you may wake up earlier than you actually want to. You might be exhausted, cranky and not hungry at the correct time for your new location. And you may find it’s hard to concentrate and that your coordination is off.

Luckily, you can manipulate your internal clock and lessen the intensity of jet lag’s effects. But to do so, you need to shift your exposure to light and darkness well in advance of your flight.

Here’s what to do:

If you are traveling east

  1. Multiply the number of time zones you will be crossing by two. This is how many days ahead of your flight that you need to start adjusting your exposure to light and darkness.
  2. Then start going to bed 30 minutes earlier per day, and getting up 30 minutes earlier per day.
  3. Make sure you get 3-4 hours of bright light immediately after you wake up each morning.

If you are traveling west

  1. Identify the number of time zones you will be crossing. This equals the number of days ahead of your flight that you need to start adjusting your exposure to light and darkness.
  2. Then start going to bed one hour later per day.
  3. Make sure you get 3-4 hours of bright light immediately before you go to bed each day.

Nervous you won’t stay on schedule?

There’s an app for that. Download Entrain on your smart phone for free.

And there are other things you can do that help with jet lag, too. Check out 9 tips from one of our sleep care experts at Methodist Hospital.