Adjusting to a nine-hour time difference involves determining one's temperature minimum and adjusting their schedule two to three days prior to travel with bright light exposure, exercise, or meals.

“Let's say I am going to travel to Europe, which is nine hours ahead typically, from California. I would want to determine my temperature minimum which for me is about 4:30 AM maybe 5:00 AM, and I would want to start getting up at about 5:30 AM and getting some bright light exposure, presumably from artificial sources because the sunlight isn't going to be out at that time. Maybe even exercising as well, maybe even eating a meal at that time if that's in your practice. You would want to start doing that two or three days before travel.”

“So if you're going to New York City from San Francisco, the best way, frankly, would be to get up an hour earlier two days before you head off to New York. And then another day, you might try and shift by two hours before you go and then head to New York and do the last shift on the last day.”

“so this is very useful if you ever want to shift your clock at home before you Trav to get onto a new schedule for work or school or if you're traveling what it means is that when you arrive in a new location like I did in Melbourne the other day believe me I practiced that for like at least an hour you know and with two aies and they kept telling me I was doing it wrong until finally they're like no I'm just joking with you you got it right like the fourth time you guys have a wicked sense of humor down here the I'm tougher than I look the the the key thing is that if you land you have to ask let's say at 8:00 a.m. local or noon local time the key is to ask yourself hm what does my body think what is my temperature minimum back from back home so for instance if you land at 5:00 p.m. but it corresponds to a time before your temperature minimum and you go outside and you're like w W beautiful Setting Sun I'm supposed to get sunlight in my eyes well guess what you might delay your clock if you want to go to bed earlier that's probably not a good idea whereas if you want to stay if you want to advance your clock you would view sunlight at a time that is corresponding to the two hours after your temperature minimum I realize it's a little bit tricky but that's all you have to ask yourself for the first three days first three days that you travel to some location because then you can shift very fast”

“You would want to start doing that two or three days before travel, because once I land in Europe, chances are, just viewing the sunrise or sunset in Europe is not going to allow me to shift my circadian clock.”