using System;

using System.Globalization;

public class Program

{

            public static string[] SupportedFormats = {

            "d/M/yyyy",

            "dd/MM/yyyy",

​

            "d/M/yyyy H:mm",

            "dd/MM/yyyy H:mm",

​

            "d/M/yyyy HH:mm",

            "dd/MM/yyyy HH:mm",

​

            "d/M/yyyy H:mm:ss",

            "dd/MM/yyyy H:mm:ss",

​

            "d/M/yyyy HH:mm:ss",

            "dd/MM/yyyy HH:mm:ss"

        };

    public static void Main()

    {

        String dateTimeString = null; //string.Empty

        DateTime result;

        if (!DateTime.TryParseExact(dateTimeString, SupportedFormats, CultureInfo.InvariantCulture, DateTimeStyles.None, out  result))

        {

                throw new FormatException("Unsupported format of DateTime");

        }

        Console.WriteLine(result);

    }

}