C#格式化 DateTime 对象

using System;

class Program
{
    static void Main()
    {
        DateTime now = DateTime.Now;

        Console.WriteLine(now.ToString("yyyy"));              // 2023
        Console.WriteLine(now.ToString("yy"));                // 23
        Console.WriteLine(now.ToString("MMMM"));              // 七月
        Console.WriteLine(now.ToString("MMM"));               // Jul
        Console.WriteLine(now.ToString("MM"));                // 07
        Console.WriteLine(now.ToString("M"));                 // 7
        Console.WriteLine(now.ToString("dd"));                // 04
        Console.WriteLine(now.ToString("d"));                 // 4
        Console.WriteLine(now.ToString("HH"));                // 10
        Console.WriteLine(now.ToString("H"));                 // 10
        Console.WriteLine(now.ToString("hh"));                // 10
        Console.WriteLine(now.ToString("h"));                 // 10
        Console.WriteLine(now.ToString("mm"));                // 30
        Console.WriteLine(now.ToString("m"));                 // 30
        Console.WriteLine(now.ToString("ss"));                // 15
        Console.WriteLine(now.ToString("s"));                 // 15
        Console.WriteLine(now.ToString("fff"));               // 123
        Console.WriteLine(now.ToString("F"));                 // 10:30:15.43
        Console.WriteLine(now.ToString("zzz"));               // +03:00 
        Console.WriteLine(now.ToString("yyyy-MM-dd"));           // 2023-07-04
        Console.WriteLine(now.ToString("yy/MM/dd"));            // 23/07/04
        Console.WriteLine(now.ToString("MMMM d, yyyy"));        // July 4, 2023
        Console.WriteLine(now.ToString("MMM d, yyyy HH:mm:ss"));  // Jul 4, 2023 10:30:15
        Console.WriteLine(now.ToString("HH:mm:ss.fff"));        // 10:30:15.123
        Console.WriteLine(now.ToString("F"));                    // Tuesday, July 4, 2023 10:30:15 AM
       


    }
}