added a textfield for birthday to signup GUI

src/main/java/SignUpGUI.java

@@ -4,7 +4,7 @@ import java.awt.event.ActionListener;
 import java.util.UUID;
 
 public class SignUpGUI extends JFrame implements ActionListener {
-	private JTextField usernameField, passwordField;
+	private JTextField usernameField, passwordField, birthdayField;
 
     public SignUpGUI() {
         setTitle("Sign Up");
@@ -27,6 +27,15 @@ public class SignUpGUI extends JFrame implements ActionListener {
         passwordField = new JPasswordField();
         passwordField.setBounds(100, 50, 160, 25);
         add(passwordField);
+        
+        JLabel birthdayLabel = new JLabel("Birthday:");
+        birthdayLabel.setBounds(20, 80, 80, 25);
+        add(birthdayLabel);
+
+        birthdayField = new JTextField();
+        birthdayField.setBounds(100, 80, 160, 25);
+        add(birthdayField);
+
     }
 
     @Override