Here in the UK we would say “I will visit you on the 19th of September” for example. I have never heard anyone say the month first. It’s just different custom. We also drive on the other side of the road…! At the beginning it would have been helpful if the world would have agreed on a standard either way. Then it would stop confusion. (And less car accidents from people on holiday/vacation on the wrong side of the road! 😅
Right, we’d automatically just say September 19th here.
It’s also why we say September 11th, and why “4th of July” is said the way it is - it’s a special day so it gets ordered differently to draw attention to it and to make it appear like a more formal holiday, since saying Day of Month is considered a more formal way of speaking here. Juneteenth also follows the Month/Day naming scheme.