LISTING 6: DATEDIFF() Query on Customer 
Table Returning Incorrect Data

CREATE TABLE dbo.Customer
(   CustomerID	int   NOT NULL IDENTITY
                                  CONSTRAINT CustomerPK
                                         PRIMARY KEY CLUSTERED,
   Birthdate  datetime  NOT NULL )
GO
INSERT INTO dbo.Customer
      VALUES ('01/01/1981 9:46 AM')
INSERT INTO dbo.Customer
      VALUES ('03/01/1981 2:12 AM')
INSERT INTO dbo.Customer
      VALUES ('05/01/1981 11:18 PM')
INSERT INTO dbo.Customer
      VALUES ('07/01/1981 4:03 PM')
INSERT INTO dbo.Customer
      VALUES ('09/01/1981 7:36 PM')
INSERT INTO dbo.Customer
      VALUES ('09/02/1981 12:03 AM')
INSERT INTO dbo.Customer
      VALUES ('11/01/1981 4:20 AM')
GO
-- Grand Opening on Sept 1, 2002 at 7:00PM
SELECT CustomerID,
      Birthdate,
      DATEDIFF(Year, Birthdate,
      CONVERT(datetime, 'Sep 01, 2002 7:00 PM'))
      AS 'Age on Sep 1, 2002'
FROM dbo.Customer
GO