The Old English Martyrology for September 24...

Records the Conception of Saint John the Baptist. Since Professor Rauer is so generous with the sharing of her work, I will presume to put here both the Old English text of the Martyrologist's work (without any of the apparatus of notes) and her translation. I remain ignorant of how widespread the celebration of the feast of Saint John's Conception was. 

On [th]one feower ond twentigo[th]an daeg [th]aes mon[th]es bi[th] Sancti Iohannis geeacnung [th]aes miclan fulwihteres. [Th]y daege Gabriel se heahengel aeteowde Zacharie, Iohannis faeder, [th]aer he stod aet [th]am weofode ond ricels baernde in Godes ansaegdnesse, ond him saegde [th]aet him scolde beon sunu acenned, and [th]aes nama scoelde Iohannis gecigged. [Th]a nolde Zacharias [th]am engle gelyfan [th]aet hym ond his wife on heora yldo meahte beon sunu acenned. [Th]a cwae[th] se engel to him: '[Th]u bist dumb o[th] [th]one daeg [th]e [th]is bi[th]'. Ond hit [th]a waes swa geworden.

On the twenty-fourth day of the month is the conception of the great baptist Saint John. On that day the archangel Gabriel appeared to Zachary, John's father, while he stood at the altar and burned incense in an offering to God, and told him that a son would be born to him, and that his name should be John. Then Zachary did not want to believe the angel, that he and his wife would have a son at their old age. Then the angel said to him: 'You shall be dumb until the day when this will happen'. And that is how it turned out. 

Have wondered how difficult it might be to add the Old English special letters to the Windows languages nonsense. Hmm. 

Occurred to me finally to search at New Liturgical Movement for 'conception, John'. Dr DiPippo in January 2016:

"... (T)he Byzantine Rite celebrates the same two principal feasts of St John as the Roman Rite, the Nativity on June 24, and the Beheading on August 29. There is also a feast of his conception, kept on September 23rd, and of the various occasions on which the relics of his head were lost and recovered, the “First and Second Finding” on February 24, and the “Third Finding” on May 25th. (The Conception of St John is occasionally found on ancient liturgical calendars in the West, but never really caught on.)"

But, in June 2020, he wrote:

"... The Baptist’s conception is noted on September 24th in many early Western calendars and martyrologies, but does not seem to have been kept as an actual feast as it is in the Byzantine Rite (one day earlier). This is because the vigil itself serves as the liturgical commemoration of his conception, the announcement of which by the Angel Gabriel to his father Zachariah is read as the Gospel of the day. This custom mirrors that of the Ember Wednesday of Advent, on which the Gospel of the Annunciation is read in preparation for Christmas...."

While I remain interested in the feast of the Conception, if it was actually celebrated anyway (as, pace Dr D., it must have been if the German Lexicon of Saints is to make sense), it appears that I must give up any imaginings about a three-fold celebration as exists for Our Lord and Our Lady.