For the average player or collector, the free online tools will correctly date most 1977–2014 Gibsons. For anything older, unusual, or potentially counterfeit, trust your eyes and an expert’s opinion over any automated result. The serial number tells you when the guitar’s serial was stamped, not necessarily when it was finished or sold. Factory delays (e.g., a 1979 serial on a 1980 model) are known to occur. Always treat the lookup result as a strong clue, not an absolute truth.