JavaFX如何获取每小时更新的Label？

Question

控制器：

package sample;

import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;

import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.ResourceBundle;
import java.util.TimeZone;

public class Controller implements Initializable {


    @FXML
    private Label daysLeft;


    @Override
    public void initialize(URL location, ResourceBundle resources) {


        Calendar calendar = Calendar.getInstance(TimeZone.getDefault());
        Date date;

        int dayOfYear;
        int hoursRemainingInDay;

        String daysLeftString;
        date = calendar.getTime();
        dayOfYear = calendar.get(Calendar.DAY_OF_YEAR);


        daysLeftString = "" + (139 - dayOfYear);
        hoursRemainingInDay = (24-getCurrentHourOfDay());


        daysLeft.setStyle("-fx-font: 48 arial");
//            daysLeft.setText(daysLeftString);
        daysLeft.setText(daysLeftString+"."+ hoursRemainingInDay);

        try {
            Thread.sleep(1_000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

    }

    public static int getCurrentHourOfDay() {

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH");
        Date date = new Date(System.currentTimeMillis());



        return Integer.valueOf(simpleDateFormat.format(date));   // Return hours of day
    }



    public void update(){



    }
}

我希望它每小时更新一次。我试过了 而（真） 睡了一个小时 但是while（true）做到了，所以窗口从未打开过。