DbfReader throws error when trying to parse NULL Date fields

[kyleeinspahr]

When evaluating the DbfReader Enumerable of a shapefile that has a Date column with NULL values, it throws the following error:
The DateTime represented by the string '00000000' is not supported in calendar 'System.Globalization.GregorianCalendar'.

Before that, I examined the Fields collection and it even reports that the Value is null:

Here is a file that shows the issue
ShapefileWithNULLDate.zip