The neck date simply refers to the date that the neck was produced.
instrument production history, production dates have been applied to various components.
Production dates have been penciled or stamped on the butt end of the heel of the neck of most guitars and basses.
There were periods of time when this was not consistently done, (between 19), and there are certainly other examples of short periods of time, and individual pieces, where the dating was simply omitted.
Neck dating is useful in determining the age of a guitar, but is not definite.
Serial numbers have been used in various locations on Fender instruments through the years.
They have been placed at the top of the neck plate, on the front of the headstock, on the back of the headstock, and on the back of the neck near where the neck bolts onto the body.
They were stamped on the back vibrato cover plate (early '50s Strats), and on the bridge plate between the pickup and the saddles on some Telecasters.
But due to the modular nature of Fender's production methods, and the fact that most serial numbers schemes are not sequential and usually overlap from between 2 to 4 years, (from the early days of Fender, through to the mid 1980s), dating by the serial number is not an exact science.
The following chart details the Fender serial number schemes used from 1950 to 1964.
There is quite a bit of overlap of numbers and years.
The only way to try to narrow the date range of your specific instrument would be to remove the neck and check the butt end of the heel of the neck for a production date, which may be stamped or written there.