Сортировка массива объектов по дате

class Flowers implements Comparable<Flowers> {
    double price;
    String name;
    String color;
    double length;
    private Calendar date;
-------------------------
@Override
    public int compareTo(Flowers that) {
        int dtCompare = this.date.compareTo(that.date);
        if (dtCompare != 0)
            return dtCompare;
 
        int priceCompare = Double.compare(this.price, that.price);
        if (priceCompare != 0)
            return priceCompare;
 
        int nameCompare = this.name.compareTo(that.name);
        if (nameCompare != 0)
            return nameCompare;
 
        int colorCompare = this.color.compareTo(that.color);
        if (colorCompare != 0)
            return colorCompare;
 
        return Double.compare(this.length, that.length);
    }
 
@Override
    public String toString() {
        return this.name + ", "  + this.color + ", "  + this.price + " руб., "  + this.length + " см., "   + new SimpleDateFormat("dd.MM.yyyy").format(date.getTime());
    }

public class Main {
    public static void main(String[] args) throws Exception {
        
        Calendar dt1 = Calendar.getInstance();
        dt1.set(2014, Calendar.OCTOBER, 14);
 
        Calendar dt2 = Calendar.getInstance();
        dt2.set(2014, Calendar.OCTOBER, 12);
 
        Calendar dt3 = Calendar.getInstance();
        dt2.set(2014, Calendar.OCTOBER, 15);
 
        Tulip tul1 = new Tulip(36.5, "красный", 50, dt1);
        Rouse ros1 = new Rouse(20, "желтый", 50, dt2);
        Violet vio1 = new Violet(55.56, "зеленый", 50, dt3);
 
        System.out.println(tul1);
        System.out.println(ros1);
        System.out.println(vio1);
        Flowers[] arr = new Flowers[3];
 
        arr[0] = tul1;
        arr[1] = ros1;
        arr[2] = vio1;
 
 
        System.out.println("Сортировка по свежести:");
        Arrays.sort(arr);
        System.out.println(arr[0]);
        System.out.println(arr[1]);
        System.out.println(arr[2]);}