Unity的获取系统时间

using UnityEngine;
using System.Collections;

public class Stime : MonoBehaviour {

    UILabel mTimeLab;
    void Start () {
        mTimeLab = this.GetComponent<UILabel>();

    }

    void Update () {
        updateTime();

    }
    void updateTime()
    {
        int hour = System.DateTime.Now.Hour;
        int min = System.DateTime.Now.Minute;
        string sHour = hour < 10 ? "0" + hour : hour.ToString();
        string sMin = min < 10 ? "0" + min : min.ToString();
        mTimeLab.text = sHour + ":" + sMin;

    }
}