BS. The 10th digit is standardized around the world to mean date of manufacture/model year on all vehicle. If a vehicle is revised the next year it will have to have a different 10th digit.
The most accurate way to get your year model is to decipher it from the 17 digit VIN number(22 if you have a Toyota). Google how to decode the VIN number of your vehicle manufacturer and get it from their. The date of first registration is the first date it was sold not the date it was...