C#枚举-枚举器定义困难

我正试图从本教程中学习C#：http://rbwhitaker.wikidot.com/c-sharp-enumerations

它建议定义"今天"，如下所示，但当我这样做时，我会得到这个错误：'EnumerationTutorial.DaysOfWeek' does not contain a definition for 'today'

我尝试过很多不同的事情，但我不明白我做错了什么。

谢谢你的帮助。

https://i.stack.imgur.com/gi4wB.png

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.IO;
using System.Net;
namespace EnumerationTutorial
{
    public enum DaysOfWeek { Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday };
    public class Program
    {
        static void Main(string[] args)
        {
            DaysOfWeek today = DaysOfWeek.Sunday;
            Console.WriteLine(DaysOfWeek.today);
            Console.ReadLine();
        }
    }
}

        DaysOfWeek today = DaysOfWeek.Sunday;

        Console.WriteLine(DaysOfWeek.today);

        Console.WriteLine(today);