In January of 2003 the serial number scheme changed from the system previously used by Gretsch Guitars.
The first two digits identify the year of production and the second two digits identify the production month.
Therefore, while helpful in determining a of production dates, a neck date is obviously not a precisely definitive reference.
Most specifications for a given Fender instrument model change little (if at all) throughout the lifetime of the model.
“Made In USA” was added to the serial number stamp and the numbers were date coded in the same way that they had been between ’65 and ’67.