Calendar.WEEK_OF_YEAR is not working correctly

Calendar.WEEK_OF_YEAR is not working correctly. My goal is every Monday is a new week. The results I am getting are in the code comments.

But I cannot find a solution.

My code:

Calendar cal = Calendar.getInstance();
//cal.setMinimalDaysInFirstWeek(7);
//cal.setFirstDayOfWeek(0);
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");

Date d = sdf.parse("27/12/2014"); //SAT
Date d1 = sdf.parse("28/12/2014"); //SUN

cal.setTime(d);
Integer weekNumber1 = cal.get(Calendar.WEEK_OF_YEAR);

cal.setTime(d1);
Integer weekNumber2 = cal.get(Calendar.WEEK_OF_YEAR);

System.out.println( weekNumber1 );// 52 
System.out.println( weekNumber2 );// 1`

      

        
        
        
      

    

second:

Calendar cal = Calendar.getInstance();
cal.setMinimalDaysInFirstWeek(7);
//cal.setFirstDayOfWeek(0);
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");

Date d = sdf.parse("27/12/2014"); //SAT
Date d1 = sdf.parse("28/12/2014"); //SUN

cal.setTime(d);
Integer weekNumber1 = cal.get(Calendar.WEEK_OF_YEAR);

cal.setTime(d1);
Integer weekNumber2 = cal.get(Calendar.WEEK_OF_YEAR);

System.out.println( weekNumber1 );// 51 
System.out.println( weekNumber2 );// 52

      

        
        
        
      

    

And third:

Calendar cal = Calendar.getInstance();
cal.setMinimalDaysInFirstWeek(7);
cal.setFirstDayOfWeek(0);
SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");

Date d = sdf.parse("27/12/2014"); //SAT
Date d1 = sdf.parse("28/12/2014"); //SUN
Date d2 = sdf.parse("29/12/2014"); //Mon

cal.setTime(d);
Integer weekNumber1 = cal.get(Calendar.WEEK_OF_YEAR);

cal.setTime(d1);
Integer weekNumber2 = cal.get(Calendar.WEEK_OF_YEAR);

cal.setTime(d2);
Integer weekNumber3 = cal.get(Calendar.WEEK_OF_YEAR);

System.out.println( weekNumber1 );// 52
System.out.println( weekNumber2 );// 52
System.out.println( weekNumber3 );// 52