Dating telecaster body
No one likes it when you forget their birthday and neither does your Fender. For most of Fender’s production history they have applied serial numbers and production dates that can help you determine their production date (within a few years’ margin, at least).
Neck dating can be useful in finding the approximate age of your guitar.
Fender Stratocaster — the "perfect rock 'n' roll machine" Keane was apparently the first person to take the screws off this Stratocaster.
(But don't worry, he's a professional.) After carefully separating the neck from the body, he found no pencil mark, suggesting this Fender was made in 1959.
Fender was sold to CBS in the first week of January 1965, but already in late 1964 mass production was slowly being introduced, which gradually lowered quality and ultimately collectibility.
It is important to remember that Fender serial numbers are NOT conclusively chronological. Back in the day, Fender made their serial number plates in big batches and the assembler simply grabbed a decal or more from the crate and slapped it on the guitar. To get as close as possible to determining the age of your Fender, make sure to check all dates on both body, neck and pots.