How can i prevent jet-lag?

Light and dark: The best strategy for jet lag involves carefully controlling exposure to light and dark in order to help your brain's internal clock make the fastest adjstment possible to the new time zone. Try searching for jet lag calculator on the internet. The best available site last time i looked was on the british airways website (but no tickets are necessary).

Depends: Traveling eastward is typically worse than westward. It also depends on the number of time zones you are crossing. If you are just crossing one or two time zones, you may just want to live with it. Crossing more than two, if you have a week to prepare, you can start living based on your new time zone, adjusting one hour each day until you are living in your new time zone BEFORE you leave. Best.