we use different units because when the british colonized us we kept the units, and just haven't changed because it's kinda pointless and would cost a lot of money
football isn't rugby, it's a different sport entirely
soccer is because when we got the sport from the british that's what they called it (this isn't just us either, soccer is used in Canada, Australia, New Zealand, Ireland, Japan, South Africa, Papua New Guinea, and the southern part of the Philippines)
and for mm/dd/yyyy idk