A friend gave me this advice,

which he and his wife tested out to good results, for a 14 hour international flight.

He said:

Someone who is both an MD and a Chinese Medicine doctor gave me the following instructions for jet lag prevention. For the first time traveling to and from Taiwan last year, we had nearly no jet lag. ... I only massage each point for about 2-5 minutes each time.

Here it is:

Yes, this is the acupressure diagram for the treatment of jet lag! This diagram shows the circadian rhythm of the meridian circulation in the body according to Chinese medicine, which shifts in two-hour intervals, one for each 時辰. Each point depicted is known as the 本穴 or "phase point" of each meridian, which embodies the intrinsic elemental qualities of that meridian and should most directly activate the circulation in that meridian alone, without simultaneously activating other meridians. Stimulating these points in sequence while time passes through the various 時辰 intervals can help adjust the body's circadian rhythm to reflect a different circadian rhythm that is currently present in another time zone.

In order to give rise to a new circadian rhythm that matches the time zone at one's destination, when you get on the airplane, you would need to calculate what time it is at the destination, and find the corresponding 時辰 on that wheel chart. Then, using a finger, knuckle or something pointier like a toothpick, you would begin to massage the representative phase point on the corresponding meridian for a few minutes.

I used a knuckle or the back end of a pen.

You only have to do one point for each time slot (you don't have to hit all the points on each diagram, just pick one convenient one), which was what I did on the airplane and a bit more after arrival.

Every two hours, you would then progress along the clock and massage the phase point on the next meridian, and so on two hours later with the next meridian, continuing every two hours at the new destination until the jet lag has ceased.

If Daylight Savings Time is in effect, it is better to go by the non-DST time rather than using the DST time.

Here is a good website for showing precise locations for each acupoint:

3-5am

經渠 Lung-8

https://www.mastertungacupuncture.org/acupuncture/traditional/points/lu8

5-7am

商陽 Large intestine-1

https://www.mastertungacupuncture.org/acupuncture/traditional/points/li1

7-9am

足三里 Stomach-36

https://www.mastertungacupuncture.org/acupuncture/traditional/points/st36

9-11am