I recently traveled to Asia for vacation. It was located at a 16 hours different time zone from home base.
It was not my first time travelling to Asia and I always had a hard time adjusting to the new time zone when I was there and when I returned home.
This time, I did something different and it helped me a lot.
On the first two days upon arriving and returning, I slept whenever I felt tired. I sleet at 3pm local time and woke up at 1am local time, but it's OK. I was not forcing myself to adjust to the local time, but let my body dictate the sleeping pattern.
On the third day, things will go by easily and much easier to adjust to the local time.
It sounds like a waste of time on the first two days, but I did enjoy the rest of the trips.