using System;

public class Program

{

    public static void Main()

    {

        Works();

        DoesntWork();

    }

    public static void Works()

    {

        DateTime? date = null;

        Console.WriteLine("This works: " + (date != null ? date.Value.Date : DateTime.Now));

    }

    public static void DoesntWork()

    {

        DateTime? date = null;

        Console.WriteLine("This won't work: " + date.Value.Date);

    }

}