This is an example of a tombstone gone wrong. :-) The tombstone of William C. Koonce (1838- 1901) of Henry County, Alabama has his death date as July 31, 1901.
However, William’s obituary was printed in the Macon Telegraph newspaper on July 31, 1901 and the story reporting his death was dated as July 20th. The story reported that he died that same day. Thus, he died July 20th and not on the 31st.