> There is no "wrong" or "right" date for Google. Google's support says to input whatever date you remember, Google will judge it as neither "true" or "false", but based on how close you are, and (this part is now speculation) combine that with other factors.

I'm sorry but you're not going to win over anybody like this. They asked you for a date, they potentially gave you some leeway for error (or not), and you gave the wrong date. Evidently your error was too high for them to overlook. You could argue they asked a bad question or should have given more leeway, and people might actually sympathize with you there, but relying instead on pedantry like this does not help.