Java 根據時間戳計算星座

/**
 * 計算星座
 * CSDN程憶難
 *
 * @param birthday
 * @return
 */
private String constellation(long birthday) {
    SimpleDateFormat simpleDateFormat = new SimpleDateFormat("Mdd");
    Date birthdayDate = new Date(birthday);
    String format = simpleDateFormat.format(birthdayDate);
    int date = Integer.parseInt(format);
    if (date >= 121 && date <= 219) {
        return "水瓶座";
    } else if (date >= 220 && date <= 320) {
        return "雙魚座";
    } else if (date >= 321 && date <= 420) {
        return "白羊座";
    } else if (date >= 421 && date <= 521) {
        return "金牛座";
    } else if (date >= 522 && date <= 621) {
        return "雙子座";
    } else if (date >= 622 && date <= 722) {
        return "巨蟹座";
    } else if (date >= 723 && date <= 823) {
        return "獅子座";
    } else if (date >= 824 && date <= 923) {
        return "處女座";
    } else if (date >= 924 && date <= 1023) {
        return "天秤座";
    } else if (date >= 1024 && date <= 1122) {
        return "天蠍座";
    } else if (date >= 1123 && date <= 1221) {
        return "射手座";
    } else {
        return "魔蠍座";
    }
}