SciVee had an interesting video from some biology researchers, who think they may have hit on an important key by watching how some animals do it in nature. This article briefly explains the basic science, then offers a video for further viewing. The tip?

bq. "Simply stop eating during the 12-16 hour period before you want to be awake. Once you start eating again, your internal clock will be reset as though it is the start of a new day. Your body will consider the time you break your fast as your new "morning."... If you are travelling from Los Angeles to Tokyo, figure out when breakfast is served in Tokyo, and don't eat for the 12-16 hours before Tokyo's breakfast time."

Useful.