There should be a date on the neck and a date on the body. If those two dates match up, thats probably the exact date your guitar was built. If they dont, it could indicate that the guitars neck was replaced at some point, or that the guitar was built from spare parts and is not an original build.

How many years is a vintage guitar?

What is a vintage guitar? While an antique is defined as an object over 100 years old, theres no strict chronological definition of what makes something vintage. Typically, though, guitars around 30 years old or older fall into that category, and even newer instruments will often be labeled as such by sellers.