There are federal regulations regarding model year versus calendar year. Remember how many manufacturers wanted to be first with a 2000 model? I'm not sure if it was the manufacturing date or the date the car could go on sale, but for the 2000 model year it was January 1, 1999 and was January 1, 2021 for the 2022 model year.

I think it's the first day the car can be sold to the public, so for 2000 the actual manufacturing date could be late '98. I recall the first was the resurrected Ford Thunderbird.

Duke