I have a PDF form that is submitted via HTTP POST (i.e. URL-encoded data). The form has a date field and the handler needs the date to be formatted as "MM/DD/YYYY". I've tried setting the field's data (and display, edit, and validation, for good measure) pattern to "date{MM/DD/YYYY}", but the field is always submitted in the format "YYYY-MM-DD". Can/how do I set the field pattern for HTTP POST?