>When a run a small test in command window and SET DATE TO AMERICAN or SET DATE TO ANSI, the result is the same. The way I test is:
>? datetime()
>In which case SET DATE TO AMERICAN would be different than SET DATE TO ANSI?

Something wrong there. My test:
under american
01-07-2023 21:57:46
under ANSI
2023-01-07 21:58:04