The Rylands fragment of the book of John was found in Egypt and dated to the year A.D. 135. As it would require several decades, for copying and circulation of this book, until it reached the Egyptian hinderland a date in the 90's makes sense. This agrees with the tradition dating of John by the early church, and the Apostle John's death in the late 90's.

Sources:
Encountering the New Testament, Walter A. Elwell / Robert W. Yarbrough, 1998, Baker Books, page 110

A Survey of the New Testament, Third Edition, Robert H. Gundry, 1994, A Survey of the New Testament, Third Edition, Robert H. Gundry, 1994, Zondervan, page 252