如何确定区域设置的日期格式是月/日还是日/月？

In my iPhone app, I'd like to be able to determine if the user's locale's date format is Month/Day (i.e. 1/5 for January fifth) or Day/Month (i.e. 5/1 for January fifth). I have a custom In my iPhone app, I'd like to be able to determ