In accordance with the Roman "Julian calendar," the "Saturnalia" festival
appears to have taken place on December 17th; it was preceded by the
"Consualia" near December 15th, and followed by the "Opalia" on
December 19th. These pagan celebrations typically lasted for a week,
ending just before the late Roman Imperial Festival for "Sol Invictus"
(Invincible Sun) on December 25th.

In 1582 AD. Roman Catholic Pope Gregory the XIII caused the current
"Gregorian Calendar" to be adopted, in order to eliminate the solar time
shift error that was introduced over the time period of 1,629 years by the
inaccurate "Julian Calendar."

By December 1582 AD the shortest day of the year on the Roman
"Julian Calendar" had shifted 12 days from Dec. 24, 46 BC. to
Wednesday, Dec. 12, 1582 AD.

However, the Original December 25th 'Birth Date' was retained for all
pagan Sun gods by the Roman "Saturnalia," "Consualia," "Opalia," and
"Sol Invictus" traditions; which were now incorporated into the Catholic
"Twelve Days of Christ-mass."

On the new Roman Catholic Gregorian calendar the shortest annual day
was numerically shifted back 10 days to the 22nd of December, where it
remains to this day; while the original order of the seven days of the week
remained unchanged.

Therefore, Wednesday, December 12th, 1582 AD, became Wednesday,
December 22nd, 1582 AD, and the True Sabbath Day (Friday sunset to
Saturday sunset) remained unchanged.

Yahweh, the Only True G_d, would never have allowed The True
Messiah to be born on or near the December 25th birthday period of the
pagan Sun gods; during the time in which virgins were sacrificed, murder
was commonplace, and orgies the norm. This would be an entirely
unacceptable association of Good and evil.

• http://www.sabbatarian.com/Birth.html