FSCalendar 任意の複数の日付の下に文字やマークを記したい。

Question

swiftで、fscalendarを使っていますが、任意の複数の日付の下に文字やマークを記したいのですが、どなたか教えてもらえませんか？

コード
import UIKit
import FSCalendar
import CalculateCalendarLogic

class ViewController: UIViewController,FSCalendarDelegate,FSCalendarDataSource,FSCalendarDelegateAppearance{

@IBOutlet weak var calendar: FSCalendar!


override func viewDidLoad() {
    super.viewDidLoad()
    // デリゲートの設定
    self.calendar.dataSource = self
    self.calendar.delegate = self

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

fileprivate let gregorian: Calendar = Calendar(identifier: .gregorian)
fileprivate lazy var dateFormatter: DateFormatter = {
    let formatter = DateFormatter()
    formatter.dateFormat = "yyyy-MM-dd"
    return formatter
}()

// 祝日判定を行い結果を返すメソッド(True:祝日)
func judgeHoliday(_ date : Date) -> Bool {
    //祝日判定用のカレンダークラスのインスタンス
    let tmpCalendar = Calendar(identifier: .gregorian)

    // 祝日判定を行う日にちの年、月、日を取得
    let year = tmpCalendar.component(.year, from: date)
    let month = tmpCalendar.component(.month, from: date)
    let day = tmpCalendar.component(.day, from: date)

    // CalculateCalendarLogic()：祝日判定のインスタンスの生成
    let holiday = CalculateCalendarLogic()

    return holiday.judgeJapaneseHoliday(year: year, month: month, day: day)
}
// date型 -> 年月日をIntで取得
func getDay(_ date:Date) -> (Int,Int,Int){
    let tmpCalendar = Calendar(identifier: .gregorian)
    let year = tmpCalendar.component(.year, from: date)
    let month = tmpCalendar.component(.month, from: date)
    let day = tmpCalendar.component(.day, from: date)
    return (year,month,day)
}

//曜日判定(日曜日:1 〜 土曜日:7)
func getWeekIdx(_ date: Date) -> Int{
    let tmpCalendar = Calendar(identifier: .gregorian)
    return tmpCalendar.component(.weekday, from: date)
}

// 特別な日
let specialDays: [String] = ["2022/01/19","2022/01/26","2022/02/02","2022/02/09"]

let specialDays2: [String] = ["2022/01/02","2022/01/03","2022/01/04","2022/12/30","2022/12/31","2023/01/03","2023/01/04"]


// 特別な日か判定
func judgeSpecialDay(_ date: Date) -> Bool {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "y/MM/dd"
    let dateString = dateFormatter.string(from: date)
    return specialDays.contains(dateString)
}

func judgeSpecialDay2(_ date: Date) -> Bool {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy/MM/dd"
    let dateString = dateFormatter.string(from: date)
    return specialDays2.contains(dateString)
}


// 土日や祝日の日の文字色を変える
func calendar(_ calendar: FSCalendar, appearance: FSCalendarAppearance, titleDefaultColorFor date: Date) -> UIColor? {
    //祝日判定をする（祝日は赤色で表示する）
    if self.judgeHoliday(date){
        return UIColor.red
    }

    //土日の判定を行う（土曜日は青色、日曜日は赤色で表示する）
    let weekday = self.getWeekIdx(date)
    if weekday == 1 {   //日曜日
        return UIColor.red
    }
    else if judgeSpecialDay2(date) {
        return UIColor.red
    }
    else if weekday == 7 {  //土曜日
        return UIColor.blue
    }
    
    else if judgeSpecialDay(date) {
        return UIColor.blue
    }
    
    return nil
}

}