using System;

using System.Globalization;

​

namespace AsyncAwait

{

    class Program

    {

        static void Main(string[] args)

        {

            var dateTimeOffset = DateTimeOffset.UtcNow;

            var dateString1 = dateTimeOffset.ToString();

            var dateString2 = dateTimeOffset.ToString("O");

​

            ParseDateIso8601(dateString1);

            ParseDateIso8601(dateString2);

        }

​

        private static void ParseDateIso8601(string dateString)

        {

            try

            {

                var date = DateTimeOffset.ParseExact(dateString, "O", null, DateTimeStyles.RoundtripKind);

                Console.WriteLine($"{dateString} IS in ISO-8601 format. Parsed Date - {date}");

            }

            catch (FormatException)

            {

                Console.WriteLine($"{dateString} IS NOT in ISO-8601 format");

            }

        }

    }

}