Gibson dating serial number
The first guitar built that day would have the production number 500.
Guitars built in the Nashville Factory from 1990 onwards have production numbers 300-999 – so the first guitar produced that day would have the production number 300.
The new system used a letter to prefix the numbers.
Guitars built in the Nashville factory from 1977 to 1989 used the production numbers 500-999.
For example, the serial number 81457556 – would be May 25 guitar built in the Nashville factory.
The 1st and 2nd indicate the year of manufacture for the 6 digit serial numbers which we've been using since 2000.
There are a number of distinct time periods for Gibson’s serial numbers, where the systems differed.
This was pretty poorly done though (IMO) and meant that some serial numbers were reused so a certain serial number could be from a guitar from different years.