DateTime “null” value

DateTime? MyNullableDate;

Nullable<DateTime> MyNullableDate;

default(DateTime)

DateTime? dt = null;

Nullable<DateTime> dt = null;

dt = new DateTime();

if (dt.HasValue)
{
  // Do something with dt.Value
}

DateTime dt2 = dt ?? DateTime.MinValue;

Nullable<DateTime> myDateTime;

DateTime? myDateTime;

DateTime? date = new DateTime?();

MyDateTime = (drOrder["Field1"] == DBNull.Value) ? (DateTime?)null : ((DateTime)drOrder["Field1"]);