date filtering not working in smart gwt

i am developing a smartGWt application that needs to filter list grid content by date and by other staff, every thing is working correctly except the date filtration, this is how i am defining the date fields :

registeredDate = new DataSourceDateField("registrationDate", voc.registeredDate());  
registeredDate.setRequired(true);

verificationDate = new DataSourceDateField("lastVerificationDate", voc.verificationDate());  
verificationDate.setRequired(true); 

the same as every other field

this is how i fill records :

registeredUsersRecords = new ListGridRecord[registeredUsers.length()];

ListGridRecord record = new ListGridRecord();
                record.setAttribute(ID, user.getId());
                record.setAttribute("firstName", user.getFirstName());
                record.setAttribute("lastName", user.getLastName());
                record.setAttribute("email", user.getEmail());
                record.setAttribute("userMainType", type);
                record.setAttribute("isActivated", (user.isActivated())? voc.active(): voc.inActive());
                record.setAttribute("country", user.getSelectedCountry().getValue());
                record.setAttribute("companyName", user.getCompanyName());
                record.setAttribute("registrationDate", user.getRegistrationDate());
                record.setAttribute("lastVerificationDate", user.getVerificationDate());
                registeredUsersRecords[i] = record;

and then i put them into datasource :

    DataSource ds = new DataSource();
    ds.setClientOnly(true);
    ds.setFields(fName, lName, email, type,typeDetails, status, country, companyName, registeredDate,verificationDate);
    for(int i = 0; i< registeredUsersRecords.length; i++){
        ds.addData(registeredUsersRecords[i]);
    }
    registeredUsersListGrid.setDataSource(ds);
    registeredUsersListGrid.fetchData();

You have not shared a complete code.

Still I am trying to provide you a sample code. Please have a look.

public class SmartGWTProject implements EntryPoint {

    public void onModuleLoad() {

        class User {
            private int id;
            private String firstName;
            private Date registrationDate;

            public User(int id, String firstName, Date registrationDate) {
                this.id = id;
                this.firstName = firstName;
                this.registrationDate = registrationDate;
            }

            public int getId() {
                return id;
            }

            public String getFirstName() {
                return firstName;
            }

            public Date getRegistrationDate() {
                return registrationDate;
            }

        }

        DateTimeFormat format = DateTimeFormat.getFormat("MM/dd/yyyy");

        User[] registeredUsers = new User[] { new User(1, "a", format.parse("01/20/2014")),
                new User(2, "b", format.parse("05/20/2013")),
                new User(3, "c", format.parse("02/20/2014")) };

        ListGridRecord[] registeredUsersRecords = new ListGridRecord[registeredUsers.length];

        for (int i = 0; i < registeredUsers.length; i++) {
            User user = registeredUsers[i];
            ListGridRecord record = new ListGridRecord();
            record.setAttribute("id", user.getId());
            record.setAttribute("firstName", user.getFirstName());
            record.setAttribute("registrationDate", user.getRegistrationDate());
            registeredUsersRecords[i] = record;
        }

        DataSourceDateField registeredDate = new DataSourceDateField("registrationDate", "Date");
        DataSourceTextField firstName = new DataSourceTextField("firstName", "Name");
        DataSourceIntegerField id = new DataSourceIntegerField("id", "ID");
        id.setRequired(true);
        id.setPrimaryKey(true);
        id.setHidden(true);

        DataSource ds = new DataSource();
        ds.setClientOnly(true);
        ds.setFields(id, firstName, registeredDate);
        for (int i = 0; i < registeredUsersRecords.length; i++) {
            ds.addData(registeredUsersRecords[i]);
        }

        ListGrid registeredUsersListGrid = new ListGrid();
        registeredUsersListGrid.setDataSource(ds);
        registeredUsersListGrid.fetchData();

        registeredUsersListGrid.draw();

    }
}