Decode MacBook assembly date from system report file?
Sign up to be a Self Servicing Account with Apple and you can look up machine PO date by serial number using their global service exchange API.


https://support.apple.com/self-servicing-account-program


That is far more reliable than trying to reverse engineer batches of serial numbers or internal components. You can also look into build details and get technical manuals / diagnostics - so this effort to get registered will pay dividends far more than a quick script.

If you really only need a quick script or don't meet the requirements for a GSX account, I would start here:


https://github.com/krypted/swiftwarrantylookup


The date isn't in the files you collected, but the serial number is which is likely the closest proxy to a build date you have at hand.