Класс Date, как правильно задать дату?

public class MainActivity extends ActionBarActivity {
    TextView Text;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Text = (TextView) findViewById(R.id.Text);
       // Date dateDemo =new Date(2015,10,10);
           Date dateDemo =new Date(2015,04,07);
           Date dateNow = new Date();//2015,05,07
        boolean demoVersionValid = dateDemo.after(dateNow);
        Text.setText("dateDemo.after(date) =  "+ demoVersionValid + "  dateDemo ="+ dateDemo.toString()+"  date ="+dateNow.toString() );
 
    }
 
 
 
 
}

Format formatter = new SimpleDateFormat("dd-MMM-yyyy hh:mm aa",Locale.ENGLISH);
s = formatter.format(dateDemo);
// s -  your date, you can show it in textview or in the log

SimpleDateFormat dateFormat = new SimpleDateFormat("dd.MM.yyyy");
Calendar calendar = Calendar.getInstance();
calendar.set(2015,4,8);
System.out.println(dateFormat.format(calendar.getTime()));