using System;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        toonDatum(DateTime.Now);

        toonDatum("08/31/2017");

​

    }

    public static void toonDatum(DateTime Datum){

        CultureInfo nlBEFormaat = new CultureInfo("nl-BE");

        Console.WriteLine(Datum.ToString("dd dddd MMMM yyyy", nlBEFormaat));

    }

    public static void toonDatum(string Datum){

            CultureInfo nlBEFormaat = new CultureInfo("nl-BE");

            DateTime dt = Convert.ToDateTime(Datum);    

            Console.WriteLine(dt.ToString("dd dddd MMMM yyyy", nlBEFormaat));

        }

}

​