h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I was talking to someone the other day who had just arrived back in NZ from Europe. They said that flying east to west is easier than flying west to east - the latter produces worse jet lag. Apparently lots of people experience this.

Is there a physically based explanation for this?

When you fly east to west, you're moving into earlier time zones. If I teleported to New York instantly right now, I would go from 1.30 am* to 8.30 pm. So effectively it's adding five hours on to my day - by the time 1.30 am came in NYC, it would be 6.30 am to my west European body. So I'd be shattered!

If someone did it the other way around, west to east, they would be skipping a few hours instead of adding them. So, they could go to bed at the usual time by the clock, but they'd effectively be having an early night.


*Sheesh, I should be in bed....

I'm not sure if that's it. The person I talked to spend several days flying to get here, so it's not like the time they arrived here had that kind of relationship to the time they left Europe.

Depends how long the flight is. Flying east to west from London to New York (time difference five hours) and going to bed at midnight NYC time on your first night is just like staying up until 5am at home, and I reckon most of us have done that more than a few times and not been jetlagged when we woke up next morning. Result - you wake up next day on NY time with no jetlag.

Flying from London to LA (eight hour time difference) is a bit more difficult because you're staying up until 8am.

Flying back to London is much harder because (if you get the redeye) you fly through the night (and don't get a lot of sleep on the plane) and arrive in the morning but your body thinks it's still around midnight and bedtime, but the local clok says 9am. Somehow you've got to get through 14 hours before it's actually bedtime where you are.

I find there are three separate issues which affect me here. Flying west from Dublin to New York:

1. I'm going on my holidays, so I can take as long as I like to adjust to the new time zone, whereas on the way back I'm back into normal life and have to be back to normal as quickly as possible so that I can work.

2. The journey to New York is during the day so I sleep before and after it. The journey back is during the night and I am unable to sleep on the plane, so I miss a whole night's sleep.

3. The effect Gosho described above - I've no problem staying up an extra 5 hours when I travel west. When I travel east, I have to go to bed five hours early, don't sleep, then have to get up five hours early having only got 1 hour instead of my usual 6.

I think jet lag is a combination of all of these and the physical effects of being on a plane, which are the same whether going east or west.

Thanks everyone, those descriptions are interesting. I talked with another friend yesterday who's also just back from Europe and she says she doesn't get jet lag at all, but that most people who do find east to west way easier than west to east. So I guess personal metabolism and brain function has a lot to do with it too.


They fly north actually, 10 hours up to Singapore, and then West for 12 hours. I did wonder if at Singapore the plane should just go up and wait for the world to turn beneath it

The only long haul I've done is UK to Japan. I find going East OK - the flight is overnight so I try to get some sleep. The day we arrive (around noon, but feeling like very early morning) I stay up as long as I can manage & get into the new time zone.

Coming back is much worse because the flight is daytime & I'm not able to sleep. So we get back to the UK at teatime but it feels like late at night. For days afterwards I wake too early & can't keep awake in the evenings.

I did a complete eastward circuit of the planet five years ago - hop to Paris, Paris-Tokyo, week in Tokyo, Tokyo-JFK, week in NYC, JFK-Manchester.

Tokyo-JFK was the worst for screwing with my body clock. No idea why, but probably related to the fact that it was my second long, long flight in a week and when I arrived it wasn't to my home. The flight home was (a) shorter and (b) to my home, so it was OK. It helped that the entire way was business class