Have you heard the local (Australian) newsreader or presenter announce the date as October 25th or worse, written like that? It's everywhere.
It would seem that the infiltration of the US is now at an all-time high, or in my books as it seems.
How on earth has this happened?
One plausible thought would have been,
Q. If I asked you what day of the week Christmas was on this year, how would you search that on a calendar? Would you go through every 25th day to December or would you first go to the month 12, day 25?
A. First you would go to the calendar for the desired year, which implies that the format should be YYYY-MM-DD. Which is precisely the format that programmers favor.
But this hasn't really answered the question as to why we have adopted this approach of late.
It's putting the thing that only changes 12 times a year before the thing that changes every day? That's so backward, right?
Or this even
Ok, let's continue.
I figure it can't be too much more than logically it must be based on the way it is said without an "of" or any extra words. Americans write it like MM DD YYYY because the day is usually said like "October 3rd, 2017." In most American English dialects folks say the month first when speaking, so it just conforms to how they talk. That's pretty much the only reason.
