"They of Basilides," says Clement, "celebrate His Baptism by a preliminary night-service of readings; and they say that 'the fifteenth year of Tiberius Caesar' means the fifteenth day of the month Tybi." It was then that the Father "in the likeness of a dove"--which they explained as meaning the Minister or Holy Spirit--came upon Him. In "the fifteenth [year] of Tib[erius]" we have, then, perhaps an interesting glimpse into the workshop of the "historicizers." [Fragments of a Faith Forgotten p. 278]
Here is the original passage in the first book of Clement's Stromata which Mead loosely quotes:
And our Lord was born in the twenty-eighth year, when first the census was ordered to be taken in the reign of Augustus. And to prove that this is true, it is written in the Gospel by Luke as follows: "And in the fifteenth year, in the reign of Tiberius Caesar, the word of the Lord came to John, the son of Zacharias." And again in the same book: "And Jesus was coming to His baptism, being about thirty years old," and so on. And that it was necessary for Him to preach only a year, this also is written: "He hath sent Me to proclaim the acceptable year of the Lord." This both the prophet spake, and the Gospel. Accordingly, in fifteen years of Tiberius and fifteen years of Augustus; so were completed the thirty years till the time He suffered. And from the time that He suffered till the destruction of Jerusalem are forty-two years and three months; and from the destruction of Jerusalem to the death of Commodus, a hundred and twenty-eight years, ten months, and three days. From the birth of Christ, therefore, to the death of Commodus are, in all, a hundred and ninety-four years, one month, thirteen days. 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 Caesar, the fifteenth day of the month Tubi; and some that it was the eleventh of the same month, And treating of His passion, with very great accuracy, some say that it took place in the sixteenth year of Tiberius, on the twenty-fifth of Phamenoth; and others the twenty-fifth of Pharmuthi and others say that on the nineteenth of Pharmuthi the Saviour suffered. Further, others say that He was born on the twenty-fourth or twenty-fifth of Pharmuthi. [Strom 1.21]
What is interesting of course is that no one has ever been able to explain why forty two and three months separate the beginning of Jesus's ministry and the destruction of Jerusalem. This would imply that the gospel was written in Alexandria for an Egyptian audience.
