I am a law school graduate. What I offer is mere information, not to be construed as forming an attorney client relationship.
What state are you in? Wow, what a weird thing to do? Yeah, if it was just one day off I would say that that wouldn't invalidate the ticket.
But to put such an old date makes no sense, unless the cop was hinting at you being able to get it dismissed.
Give us the state and county you received the ticket and let us see if we can find a code covering this type of mistake.