I don't know your particular situation, but often it took a while for a will to be probated, especially when there was real estate which needed to be sold to fulfill the bequests in the will, and perhaps the will in question was finally probated and this date was the final date when the file was complete. Another possibility I know of in the case of my 2ggrandfather was that he died in Franklin County, Ohio but owned property in Licking County Ohio. So a copy of his will was sent to the court house in Licking County, Ohio. I'd have to look at it to see if the date of this copy was much later than his death.