What year was my guitar made?

If you have a Fender Jag-Stang use the Serial Lookup Tool in the Registry:
Fender Jag-Stang Serial Number Lookup Tool

For other Japan made Fender guitars see this page:
Japanese Serial Number Dates
and this japan page

For those american made Fenders guitars see this page:
American Serial Number Dates

Mexican made guitars generally follow the following rules:
ex MN812323 – the first 3 characters are whats important
[M] = made in Mexico
[N] = 90’s (Z means zero for 2000, etc…)
[8] = year 8
= Mexico 1998

more examples… [MZ1XXXXX] = 2001, [MN4XXXXX] = 1994
Also see this page for Mexican serials

For any fender, if you want the exact year you will need to check the date stamped on the butt end of the neck. To do that you will need to remove the neck from the guitar or at least loosen it enough so the date can be seen.