Errors and Solution

Error 1:

string isEmpty = string.Empty;
DateTime dt = isEmpty == string.Empty ? BNull.Value : DateTime.Now;

Error
Type of conditional expression cannot be determined because there is no implicit conversion between 'System.DBNull' and 'System.DateTime'

Solution
Cast it to object.

string isEmpty = string.Empty;
DateTime dt = Convert.ToDateTime(isEmpty == string.Empty ? (object)DBNull.Value : (object)DateTime.Now);