using System;

public class Program

{

    public static void Main()

    {

        DateTime dt;

​

        DateTime.TryParseExact("21/4/2019 11:6:56",

                       "dd/M/yyyy hh:m:ss",

                        System.Globalization.CultureInfo.InvariantCulture,

                        System.Globalization.DateTimeStyles.None,

                        out dt);

        Console.WriteLine(dt);

    }

}