java date handling

Calendar c = Calendar.getInstance();
   
 System.out.println(c.getTime());
    
c.set(Calendar.MONTH, c.get(Calendar.MONTH)+1);
   
 c.set(Calendar.DAY_OF_MONTH, 1);
   
 System.out.println("First day of next month: " + c.getTime());
   
 c.set(Calendar.MONTH, c.get(Calendar.MONTH)+1);
   
 c.set(Calendar.DAY_OF_MONTH, 0);
   
 System.out.println("The last day of next month: " + c.getTime());

Date comparison: compareTo(calendar strength);