using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text;namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {

            string ISO8601time = DateTime.Now.ToString("yyyy-MM-ddTHH:mm:sszzzz", DateTimeFormatInfo.InvariantInfo);
            string ISO8601time1 = DateTime.UtcNow.ToUniversalTime().ToString("yyyy-MM-ddTHH:mm:ssZ");
            string ISO8601time2 = DateTime.Now.ToString("yyyy-MM-ddTHH:mm:ss.fffffffzzzz", DateTimeFormatInfo.InvariantInfo);
            string ISO8601time3 = DateTime.UtcNow.ToUniversalTime().ToString("yyyy-MM-ddTHH:mm:ss.fffffffZ");
            Console.WriteLine(ISO8601time);
            Console.WriteLine(ISO8601time1);
            Console.WriteLine(ISO8601time2);
            Console.WriteLine(ISO8601time3);
            Console.Read();
        }
    }
}

结果：

龙腾一族至尊龙骑