St.John's day.

Third day in the octave.
"This is John, to whom Christ on the cross commended his Mother, the Virgin to a virgin."
-Second antiphon, Lauds of the office of St.John

"O God, who didst open the secrets of thy Word to us through blessed John the apostle, grant we beseech thee, That what he poured into our ears in so excellent a manner, we may grasp with the learning of a competent mind."
-Collect of the day, Liturgia Horarum.