using System;

public class Program

{

    public class X

    {

        public DateTime? Y;

    }

    public static void Main()

    {

        var xx = new X();

        // Value not set

        if (xx.Y.HasValue)

        {

            Console.WriteLine("1 w00t");

        }

        else

        {

            Console.WriteLine("1 haha");

        }

        // Value set to null

        xx.Y = null;        

        if (xx.Y.HasValue)

        {

            Console.WriteLine("2 w00t");

        }

        else

        {

            Console.WriteLine("2 haha");

        }

        xx.Y = DateTime.MinValue;

        if (xx.Y.HasValue)

        {

            Console.WriteLine("3 w00t");

        }

        else

        {

            Console.WriteLine("3 haha");

        }

    }

}