Guides
Some of these help you find the number in the first place. The rest take over when the number alone can't date an instrument.
How Fender serial numbers got this complicated
How Fender's numbering changed from 1950s neck plates to headstock decals, and what a number from the US, Mexico, Japan, Korea or Indonesia can actually tell you.
What to check when a Gibson serial can't be dated
Three checks that still date a Gibson from 1961 to 1975, in the order that narrows the span fastest: the stamp under the number, the pot codes, the headstock.
Made in Japan or Crafted in Japan: the wording is the answer
One Fender Japan serial letter can cover more than one span of years. The words printed beside the number are what separate them. Here is where to read them.
Where to find the serial number on your instrument
Where the serial number sits on a Fender, Gibson, Martin, Taylor, PRS or Squier, and what to read instead when the one you find carries no year.
How to read a pot code
The code stamped on a guitar pot names the maker and the week the part was made. How to read the digits, and how far that date carries to the instrument itself.