来自MSDN的数据示例：

Dim dateString,format As String  
Dim result As Date
Dim provider As Globalization.CultureInfo = Globalization.CultureInfo.InvariantCulture

' Parse date and time with custom specifier.
dateString = "20090910"
format = "yyyyMMdd"        
Try
   result = Date.ParseExact(dateString,format,provider)
   Console.WriteLine("{0} converts to {1}.",dateString,result.ToString())
   Console.ReadLine()
Catch e As FormatException
   Console.WriteLine("{0} is not in the correct format.",dateString)
End Try