Date, Date?, and the ToString Method in VB.Net

This article discusses a common pitfall in VB.Net where developers confuse the Date type with the Nullable Date type (Date?). The author describes a frustrating 45-minute debugging session caused by an InvalidCastException when trying to use a format string with ToString() on a Date? object. The key insight is that Date and Date? have different ToString() overloads; only the non-nullable Date type accepts a format string. The solution involves wrapping the Date? instance in a CType conversion to Date before calling ToString() with the desired format. The article is a technical tutorial aimed at VB.Net programmers and is directly related to IT/technology.