using UnityEngine;

using System.Collections;

public class   Test01  : MonoBehaviour {

                          private float timer = 0f;

                          private int h = 0;

                          private int m = 0;

                          private int s = 0;

                          private string timeStr = string.Empty;

void Update ()

{

                  timer += Time.deltaTime;

                  if (timer >= 1f)

                   {  s++;

                      timer = 0;}

                  if (s >= 60)

                  {  m++;

                      s = 0;}

                 if (m >= 60)

                  {h++;

                   m = 0;}

                if (h >= 24)

                    {h = 0;}

}

void OnGUI()

{

            timeStr = string.Format ("{0:D2}:{1:D2}:{2:D2}", h, m, s);

          GUI.Label (new Rect (10, 10, 100, 200), timeStr);

}

}