/**  
	     * 計算兩個日期之間相差的天數  
	     * @param smdate 較小的時間 
	     * @param bdate  較大的時間 
	     * @return 相差天數 
	     * @throws ParseException  
	     */    
	    public static int daysBetween(Date smdate,Date bdate) throws ParseException    
	    {    
	        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");  
	        smdate=sdf.parse(sdf.format(smdate));  
	        bdate=sdf.parse(sdf.format(bdate));  
	        Calendar cal = Calendar.getInstance();    
	        cal.setTime(smdate);    
	        long time1 = cal.getTimeInMillis();                 
	        cal.setTime(bdate);    
	        long time2 = cal.getTimeInMillis();         
	        long between_days=(time2-time1)/(1000*3600*24);  
	            
	       return Integer.parseInt(String.valueOf(between_days));           
	    }