How Does Two Days of Light Cover a Nine-hour Jump?

Andrew Huberman says the temperature minimum is the anchor for shifting sleep before a trip to Europe. In the two or three days before departure, set an alarm, wake up around that temperature minimum, maybe an hour before, and turn on bright lights at home. Bright light exposure starts to shift the clock forward. A nine-hour jump can be accomplished in about two days when the timing is done correctly. The reverse is also true, so the clock can shift earlier as well.

After landing in Europe, the clock back home matters more than the new environment. Light viewed in the hour or two before the temperature minimum makes a person want to go to sleep later and wake up later. Light viewed after the temperature minimum makes a person want to go to sleep earlier and wake up earlier.