The American order of writing dates as a legacy of the British colonial period
If We Write It the American Way, Today Is 123123.
Writing the date back to front, with the month ahead of the day, is no original American invention: it is a relic of an old colonial custom left over from the days of British rule. The British themselves abandoned such notation more than a hundred years ago, and now write as the whole world does: day-month-year. The United States, as usual, distinguished itself. On the other hand, it is as well that they remember their numerals