It is obvious that java.util.Date is mapped to xs:dateTime.
Lets see what happens when we generate the client stubs from the wsdl. (This is done by right clicking the project in Netbeans and selecting New Web Service Client and entering the wsdl to the related input.)
The generated stubs are at the following location:
Java.util.Date becomes javax.xml.datatype.XMLGregorianCalendar when xml is mapped to Java types againL (Comments are omitted from the following generated code for simplicity..)