@Pete ******
I know about what the question is, but your reply suggests that you become tax resident at the moment you are RESIDENT for 180 days or more.
That just is factual not true.
I quote: become Thai tax residentâ means being resident in the Kingdom for 180 days in a calendar year
Also you do not become tax resident at a certain moment, you are tax resident in a certain calendar year, you can be tax resident in one year and not in the next year.