Android_Date_Picker.java

static final int dialog_id = 0;
int year_x, month_x, day_x;


final Calendar cal = Calendar.getInstance();
year_x = cal.get(Calendar.YEAR);
month_x = cal.get(Calendar.MONTH);
day_x = cal.get(Calendar.DAY_OF_MONTH);

// call 'showDialog(dialog_id)' method for show data picker

@Override
protected Dialog onCreateDialog(int id){
	if(id == dialog_id) {
		return new DatePickerDialog(your_activity.this, kDate, year_x, month_x, day_x);
	}
	return null;
}

private DatePickerDialog.OnDateSetListener kDate = new DatePickerDialog.OnDateSetListener() {
	@Override
	public void onDateSet(DatePicker datePicker, int i, int i1, int i2) {
		year_x = i;
		month_x = i1 + 1; // month start from 0 that why we add 1
		day_x = i2;

		// what we want to do
	}
};

// dialog_id, year_x, month_x, day_x, cal, kDate