Java で Zellers Congruence を使用して曜日を見つける

public class FindDay {
  // A method to print a day for a Date
  static void ZellerCongruence(int Day, int Month, int Year) {
    if (Month == 1) { // Checking the month if it's "January"
      Month = 13;
      Year--;
    }
    if (Month == 2) { // Checking the month if it's "February"
      Month = 14;
      Year--;
    }

    int DD = Day;
    int MM = Month;
    int yy = Year % 100;
    int YY = Year / 100;
    // Calculating the day
    int Calc = DD + 13 * (MM + 1) / 5 + yy + yy / 4 + YY / 4 + 5 * YY;

    Calc = Calc % 7; // Finding the day

    switch (Calc) {
      case 0:
        System.out.println("The day is: Saturday");
        break;
      case 1:
        System.out.println("The day is: Sunday");
        break;
      case 2:
        System.out.println("The day is: Monday");
        break;
      case 3:
        System.out.println("The day is: Tuesday");
        break;
      case 4:
        System.out.println("The day is: Wednesday");
        break;
      case 5:
        System.out.println("The day is: Thursday");
        break;
      case 6:
        System.out.println("The day is: Friday");
        break;
    }
  }

  // Our main class
  public static void main(String[] args) {
    ZellerCongruence(20, 9, 2022); // The date format is (dd/mm/yyyy)
  }
}

The day is: Tuesday