Dates in castor are a little bit tricky. I'm not quite sure but I think
castor itself saves the values in some kind of string format yyyy-mm-dd

So I recommend to format your date as a string in xsd-file.
<xsd:element name="AccessDate" type="xsd:string"/>

If you read the string date values use this method:

public static void setAccessDate(String selValue) {
   Date calcDate;

   try {
       //Set input format of string date
       java.text.SimpleDateFormat sdfInput = new
java.text.SimpleDateFormat(
           "yyyy-MM-dd");

       //Convert date in string format to date format
       calcDate = sdfInput.parse(selValue);
     }
     catch (Exception e) {
       //Set date on today
       calcDate = (new Date());
     }
   }

   //Set value of input field
   datefieldAccessDate.setValue(calcDate);
 }

If you write back to castor, first convert date values in your application
to string values in this format. You could use the following function for
this task.

public static String getAccessDate() {
   //Convert date to string in format yyyy-MM-dd
   java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(
       "yyyy-MM-dd");
   String convertedDate = sdf.format(datefieldAccessDate.getValue());

   //Return the converted date
   return convertedDate;
 }

Regards,
Chris