“All which shews that these days were fixed in the first Christian Calendars by Mathematicians at pleasure, without any ground in tradition; and that the Christians afterwards took up with what they found in the Calendars”

Vol. I, Ch. 11: Of the Times of the Birth and Passion of Christ
Observations upon the Prophecies of Daniel, and the Apocalypse of St. John (1733)
Context: The times of the Birth and Passion of Christ, with such like niceties, being not material to religion, were little regarded by the Christians of the first age. They who began first to celebrate them, placed them in the cardinal periods of the year; as the annunciation of the Virgin Mary, on the 25th of March, which when Julius Cæsar corrected the Calendar was the vernal Equinox; the feast of John Baptist on the 24th of June, which was the summer Solstice; the feast of St. Michael on Sept. 29, which was the autumnal Equinox; and the birth of Christ on the winter Solstice, Dec. 25, with the feasts of St. Stephen, St. John and the Innocents, as near it as they could place them. And because the Solstice in time removed from the 25th of December to the 24th, the 23d, the 22d, and so on backwards, hence some in the following centuries placed the birth of Christ on Dec. 23, and at length on Dec. 20: and for the same reason they seem to have set the feast of St. Thomas on Dec. 21, and that of St. Matthew on Sept. 21. So also at the entrance of the Sun into all the signs in the Julian Calendar, they placed the days of other Saints; as the conversion of Paul on Jan. 25, when the Sun entered Aquarius; St. Matthias on Feb. 25, when he entered Pisces; St. Mark on Apr. 25, when he entered Taurus; Corpus Christi on May 26, when he entered Gemini; St. James on July 25, when he entered Cancer; St. Bartholomew on Aug. 24, when he entered Virgo; Simon and Jude on Oct. 28, when he entered Scorpio: and if there were any other remarkable days in the Julian Calendar, they placed the Saints upon them, as St. Barnabas on June 11, where Ovid seems to place the feast of Vesta and Fortuna, and the goddess Matuta; and St. Philip and James on the first of May, a day dedicated both to the Bona Dea, or Magna Mater, and to the goddess Flora, and still celebrated with her rites. All which shews that these days were fixed in the first Christian Calendars by Mathematicians at pleasure, without any ground in tradition; and that the Christians afterwards took up with what they found in the Calendars.