Java SE (Java Platform, Standard Edition)

In program at the end I get a window and empty space below upper frame of the window and above the number in the window. Can anyone please help me get rid of that empty space? That is, how can I move the number higher a bit?

import java.awt.*;
import javax.swing.*; 

public class ShowTime extends JFrame
{
    public static void main(String[] arguments) {
        ShowTime frame = new ShowTime();
        frame.pack();
        frame.setVisible(true);
    }

    JLabel lTime;
    public ShowTime() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        JPanel pane = new JPanel();
        pane.setLayout(new FlowLayout());
        
        lTime = new JLabel("88:88");
        lTime.setFont(new Font ("Helvetica", Font.PLAIN, 88));
        pane.add(lTime);
        setContentPane(pane);
    }
}