using System;

public class Program

{

    public static void Main()

    {

        var dateToConvert = DateTime.UtcNow;

        Console.WriteLine("in file style:");

        string inFileTimeStyle = (dateToConvert.ToString("yyyy-MM-ddTHH:mm:ss.fffZ", System.Globalization.CultureInfo.InvariantCulture));

        Console.WriteLine(inFileTimeStyle);

​

        Console.WriteLine("Read back in file style:");

        DateTime converted_inFile = DateTime.ParseExact(inFileTimeStyle, "yyyy-MM-ddTHH:mm:ss.fffZ", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.RoundtripKind);

        Console.WriteLine(converted_inFile.ToString("o", System.Globalization.CultureInfo.InvariantCulture));

​

        Console.WriteLine("\nfilename style");

        string fileNameTimeStyle = (dateToConvert.ToString("yyyyMMddTHHmmssfffZ", System.Globalization.CultureInfo.InvariantCulture));

        Console.WriteLine(fileNameTimeStyle);

​

        Console.WriteLine("Read back filename style");

        DateTime converted_fileName = DateTime.ParseExact(fileNameTimeStyle, "yyyyMMddTHHmmssfffZ", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.RoundtripKind);

        Console.WriteLine(converted_fileName.ToString("o", System.Globalization.CultureInfo.InvariantCulture));

    }

}