Custom Date Field DD/MM/YY not MM/DD/YY
So this seems to be an internationalization issue. In the US it is standard for Date fields to be MM/DD/YY and your date field is DD/MM/YY which might confuse users if they see something like 24/06/2015. It took me a second to understand what was going on.
Now, I did test out typing 2/14/2016 and hitting submit. Even though the calendar widget did not change to reflect the date (which it changes id you use the DD/MM/YY format) it did save the correct Feb. 14, 2016 date to that field.
So this seems to be a display issue. So it is not a high priority, but it would be nice if Dates could be displayed in MM/DD/YY format in custom fields.