OK, but who would use 12h time ? I never understood, this seems so backwards.
How about someone who was raised on 12h time and has used it for 70 years? Sure, the math to convert is pretty easy, but why?
Americans. The U.S. has a lot of people who are unaccustomed to 24 hour time.
People who can't reliably subtract 12 from numbers. They're out there.