Hey, try this on for size. This will not speak to your situation today, with computerized reservations, but I have in my possession an old ticket stub for the wrong YEAR.
It is an old pre-Amtrak ticket, way before computerized reservations. It was for a return trip in January,(which had begun in December) don't remember the year, but the agent manually wrote in the year ending in December, for a return in January.
You know how we all have trouble remembering to write in a new year? Anyway this was for a return ticket on, say, Jan. 5, 1964, and the agent wrote in like 1963.
The conductor didn't even notice it (or perhaps he knew it was an innocent mistake and didn't say anyting). In fact I did not even notice it until I got home.