"He points out that the ancient Roman religions had no winter solstice festival."
Saturnalia (from the god Saturn) was the name the Romans gave to their holiday marking the Winter Solstice.
______________________________________________
Next book he should write explains how Saturn'sDay, SunDay, and MoonDay are really not Roman at all.
/end sarcasm
Or how Tiu's Day, Woden's Day, Thors' Day or Frie's Day have nothing to do with the Germanic gods!
Scholarly theories of a pagan origin of Christmas point to the “Birth of the Unconquered Sun” on Dec. 25th, NOT Saturnalia (which was a made-up feast anyway...not an ancient religious rite) on Dec. 17th, as the supposed origin.
This article just points out that there are clues that Christians celebrated Jesus birth on Dec. 25 (never earlier in Dec...) well BEFORE the Roman Emperor made the date into another Roman holidy.
The Gospel of Luke though gives us a clue...in Ch. 1 vs. 5, that Zachariah, John the Baptist’s father, conceived John right after his priestly duty as part of the “division of Abijah.” The reason this hasn’t been definitive...is the exact documented timing of when each division served is lost to us today... However, it would NOT of been lost to those Christians in the 2nd and 3rd Centuries when the date of Jesus birth became established.
According to Messianic Jewish sources today—using their best educated guess-—the timing of the service of the “division of Abijah” puts Jesus birth (6 months after John’s) as either in the Spring, or, late December.
The Church overwhelmingly...from early on...as put Jesus birth in late Dec. (or early January—differences in Calendars East and West), therefore there is no reason to really not to accept that date.