如何为for循环中生成的所有日期设置通知

    String date = "28/04/2018";
    SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
    Calendar c = Calendar.getInstance();
    try {
        c.setTime(sdf.parse(date));
    } catch (ParseException ex) {
        Logger.getLogger(PondDaily.class.getName()).log(Level.SEVERE, null, ex);
    }
    int maxDay = c.getActualMaximum(Calendar.DAY_OF_YEAR);
    for (int co = 0; co < maxDay; co++) {
        System.out.println(sdf.format(c.getTime()));
        c.add(Calendar.DATE, 21);

    }
    String date = "28/04/2018";
    SimpleDateF