日期时间

time.text = System.DateTime.Now.ToString("HH:mm");
date.text = System.DateTime.Now.ToString("yyyy年MM月dd日");
timeText.text = System.DateTime.Now.ToString("HH:mm");
dateText.text = System.DateTime.Now.ToString("yyyy/MM/dd dddd", new System.Globalization.CultureInfo("zh-cn"));
// dateText.text = System.DateTime.Now.ToString("dddd", new System.Globalization.CultureInfo("zh-cn"));

==================
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class Timertt : MonoBehaviour {
private Text timer;//时间
//private float time;//游戏已经运行时间
private float startTime;//游戏开始的时间

void Start () {
    timer = transform.Find("Timer").GetComponent<Text>();
    //得到游戏开始的时间；单位：秒
    startTime = Time.time;
}   
void Update () {
    //游戏已经运行的时间=当前游戏时间跟游戏开始的时间的差，单位：秒
    float time = Time.time - startTime;
    //秒
    int seconds=(int)(time%60);
    //分
    int minutes = (int)(time/60);
    //游戏已经运行时间
    string strTime = string.Format("{0:00}:{1:00}",minutes,seconds);

    timer.text = strTime;

}

}