I have an interesting task before me on a site that I have developed and host. I am trying to set a fictional year represented by a "YC" and appended by "114". Now, I have got it to work, but it appears to be finicky in that it will change by a year in either direction.
I did find a guide that is doing the exact same thing that I worked out:
http://studiohyperset.com/wordpress-old-dates-historical-pre-1969-pre-1970-timestamp-function/3102
So for those searching Google for the same, here you go. Good luck! Now I'm off to perfect this year!