Format nullable Date field in View in ASP.Net MVC

I have null date, but in table showing 01/01/0001

view

@Convert.ToDateTime(item.employee.Passport_Expiry_Date).ToString("dd/MM/yyyy")

Model

[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public Nullable<DateTime> Passport_Expiry_Date { get; set; }