calculate difference dates 360 days years - 30 day month

/*
* calculate difference between dates taking in consideration these points:
* - 1 year = 360 days
* - 1 month = 30 days
* - results must be rounded up with two decimals
*/

// import java.util.*;
public static void main(String[] args) throws Exception {

    calculateDate("27/11/2017", "03/02/2020");
    calculateDate("04/12/2017", "17/08/2022");
    calculateDate("08/12/2017", "17/04/2021");
    calculateDate("15/12/2017", "17/10/2019");
    calculateDate("16/12/2017", "17/09/2019");
    calculateDate("16/12/2017", "17/12/2018");
    calculateDate("19/12/2017", "17/04/2018");
    calculateDate("19/12/2017", "17/11/2018");
    calculateDate("20/12/2017", "17/05/2018");
    calculateDate("20/12/2017", "17/04/2018");
    calculateDate("29/12/2017", "17/02/2020");
}

private static void calculateDate(String startDateStr, String endDateStr) throws ParseException {
    System.out.println(System.lineSeparator()+"==========START==========");
    Date dateStart = new SimpleDateFormat("dd/MM/yyyy").parse(startDateStr);
    Calendar cal = Calendar.getInstance();
    cal.setTime(dateStart);
    int year1 = cal.get(Calendar.YEAR);
    int month1 = cal.get(Calendar.MONTH) +1;
    int days1 = cal.get(Calendar.DAY_OF_MONTH);

    Date end = new SimpleDateFormat("dd/MM/yyyy").parse(endDateStr);
    cal = Calendar.getInstance();
    cal.setTime(end);
    int year2 = cal.get(Calendar.YEAR);
    int month2 = cal.get(Calendar.MONTH) +1;
    int days2 = cal.get(Calendar.DAY_OF_MONTH);


    double daysTotal =  (360*(year2-year1)+30*(month2-month1)+(days2-days1));
    double monthsTotal = daysTotal/30;
    double yearsTotal = daysTotal/360;

    System.out.println("start: "+ dateStart.toString() + " end: "+  end.toString());
    // round to 2 decimals
    System.out.println("days total: " + (Math.round(daysTotal)) +
             " month : "+ (Math.round(monthsTotal)) + " years total: "+ yearsTotal);
    System.out.println("==========END==========");
}