2 occurrences across the corpus

Apostolic Fathers

Ignatius to the Romans 3:15

This have I written to you, the day before the ninth of the calends of September. Be strong unto the end, in the patience of Jesus Christ. To the Romans.

NT Apocrypha/Pseudepigrapha

Acts of Paul and Thecla 11:17

The day which is kept sacred to her memory, is the twenty-fourth of September, to the glory of the Father, and the Son, and the Holy Ghost, now and for evermore. Amen.