How do you cope? I live in GMT-6 and we are flying today to GMT+1. I shift my wake up time, getting up about 2-3 hrs earlier for a couple days in advance which won't make up for the other 4-5 hours, but I think that helps ease the pain. I don't think it's practical to adapt to the new time zone while on the plane. You are going to be tired, you need sleep. Pulling an all nighter imo, does not help, if you expect to be functional on the first day there. If I can get 5 hrs sleep on the airplane, I'm doing well on the other end. I don't know if melatonin is a good idea for the plane if you are going to get less than a full night's sleep (on the plane), but it may help for bed time after you arrive. That has not seemed to be an issue for me in the past. However if it's 11pm local, while back home it's 4pm, melatonin might be a consideration if you find yourself staying awake. The only thing is you have to take it an hour or two before you intend on going to bed. WebMD says: 1. Simulate your new schedule before you leave. 2. Adapt to your new schedule while in flight. 3. Arrive early. 4. Stay hydrated. 5. Move around. 6. Consider melatonin. 7. Try natural light therapy. 8. Eat sensibly. 9. Take a hot bath before bedtime. 10. Minimize sleep distractions. 11. Consider medication.