I can't do math with calendar method in Java, but got the "java: bad operand types for bin-CodePudding

I'm trying to make a code that tells me how many days left for me to go college, but I am not able to do it with the current date. I can easily make it by setting a date, but I want the current date, so I have to use the calendar method, but can't do math using it. My code:

    SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
    Calendar calendar = Calendar.getInstance();
    Date start = sdf.parse("10/06/2022");
    System.out.println(start - calendar.getTime());

CodePudding user response：

    Calendar calendar = Calendar.getInstance();   
    Calendar collegeDate = Calendar.getInstance();
    collegeDate.set(Calendar.DATE,10);
    collegeDate.set(Calendar.MONTH, 5);
    collegeDate.set(Calendar.YEAR, 2022);
    System.out.println(Duration.between(calendar.toInstant(), collegeDate.toInstant()).toDays());

CodePudding user response：

You can try this

        SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
        Calendar calendar = Calendar.getInstance();
        Date start = sdf.parse("10/06/2022");

        long dif = Math.abs(calendar.getTimeInMillis() - start.getTime());
        long result = TimeUnit.DAYS.convert(dif, TimeUnit.MILLISECONDS);

        System.out.println(result);