Hence the author of Mcn was obliged to mention Pilate only because of the "15° year of Tiberius", in turn a derivation from 15° of Tybi.
Giuseppe wrote: ↑Fri Apr 12, 2019 6:28 am
And there are those who have determined not only the year of our Lord's birth, but also the day; and they say that it took place in the twenty-eighth year of Augustus, and in the twenty-fifth day of Pachon. And the followers of Basilides hold the day of his baptism as a festival, spending the night before in readings.
And they say that it was the fifteenth year of Tiberius Cæsar, the fifteenth day of the month Tybi; and some that it was the eleventh of the same month.
http://www.newadvent.org/fathers/02101.htm