Android實現一個日期處於某個時間段

SimpleDateFormat   formatter   =   new   SimpleDateFormat   ("HH:mm:ss");      
Date   cur1   =   new   Date(System.currentTimeMillis());
String   str   =   formatter.format(cur1);

SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");

try {
cur = sdf.parse(str);
daystart = sdf.parse("08:00:00");
dayend = sdf.parse("18:00:00");
nightstart1 = sdf.parse("20:00:00");
nightend1 = sdf.parse("23:59:59");
        nightstart2 = sdf.parse("00:00:00");
nightend2 = sdf.parse("06:00:00");
} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
   }

if((cur.equals(daystart) || cur.after(daystart)) && (cur.equals(dayend) || cur.before(dayend))){
System.out.println("白天8點到18點");

}else if(((cur.equals(nightstart1) || cur.after(nightstart1)) && (cur.equals(nightend1) || cur.before(nightend1)))
||((cur.equals(nightstart2) || cur.after(nightstart2)) && (cur.equals(nightend2) || cur.before(nightend2)))){

System.out.println("晚上20點到6點");
  }