Different people’s biological clock adjust at different rates. Generally it’s 1 day per hour of time zone difference.
So from Los Angeles it’s 12+
***
=14-15 hours time zone difference.
I find it takes about a week to adjust to arriving in Thailand and about 2 weeks on returning to Los Angeles.
You can help your clock adjust by having a lot of daylight during the daytime of your new place and really limiting bright light at night time.
Also try to have a quiet place for sleeping.
Melatonin is the sleep hormone that adjusts the clock.
It is helpful to take it at your new bedtime.
Don’t push yourself too hard.