I was recently going through currency I got back in change when I found a serial number reading FG 04072005 B printing year is 2003 A I was curious if the bill carried any premium considering that it could actually be an exact birthday rather than just a year? I'm new to the paper money currency thing. Fun side fact, apparently on that exact date Wrestle Mania was going on in 2005. Funny coincidence.
I don't know of anyone who has actually purchased a birthday note, despite seeing tons on eBay. I'm sure there's someone with that birthday that would pay $5 for a $5 bill for the novelty. Whether they'll pay a premium is the unknown.
I would say there would be a small market for it. Now if you had hundreds like that you could make something of it. If anything I would keep it, not a terribly early not but not to late of one either.