I've learned the hard way that this is also dependent on the user's date format set on their computer in some libraries(iirc it was jquery ui date picker a few

I've learned the hard way that this is also dependent on the user's date format set on their computer in some libraries(iirc it was jquery ui date picker a few years back). its liberating when you decide to throw it all out and just use integers for all things not facing an end user.