The latest research indicates that sleep deficit is the critical variable.

1. Be sure that you are well rested before you start the trip, and that any sleep deficit is made up.

2. While travelling, sleep as much as you can--short term sleeping tablets help--4-5 hours across the Atlantic is possible.

3. When you arrive, go to sleep as soon as is reasonably possible--you can wait a bit, for lunch, brief meeting etc, or if you must have your meeting, etc., and go to bed at ,say, 7pm, or whatever. Try to sleep through to the following morning, but ,say, 4am will do.

4. Go about your business in a normal way, having a nap if required from time to time.

The idea is that if you are well rested, you 'clock' will more or less look after itself.