When the Church says that, in the dogmas of religion, reason is totally incompetent and blind, and its
use to be reprehended, it is in reality attesting the fact that these dogmas are allegorical in their nature, and are not to
be judged by the standard which reason, taking all things sensu proprio , can alone apply. Now the absurdities of a
dogma are just the mark and sign of what is allegorical and mythical in it. ... [T]he difficulty is to teach the multitude that something can be both
true and untrue at the same time. And as all religions are in a greater or less degree of this nature, we must recognize the
fact that mankind cannot get on without a certain amount of absurdity, that absurdity is an element in its existence, and
illusion indispensable; as indeed other aspects of life testify.
Even Evola, in 'Roma e il natale solare nella tradizione nordico-aria' (La Difesa della razza, 1940) made a little "lapsus calami" when he wrote that the 25 December is the day of the winter solstice, while it just symbolizes it.
Xmas, is celebrated now about 4 days after the true astronomical solstice (solar ingress into Capricorn). In Rome, after the beginning of the Saturnalia, the day of the solstice was dedicated to the goddess Angerona, the one who overcomes the "angustiae", the fears of the longest night of the year. The emperor Aurelianus initiated the Natalis Solis Invicti related to the solar god Mithras, the favourite of the legionaries, just the 25 December, to which Christianity merely superimposed its Nativity.
Now, why Aurelianus chose the day 25 for celebrating the feast-day of the Sun, instead of simply remove Angerona from the calendar at the solstice? It's not clear.
By the way, an oddity of the Christian Xmas is that St. Luke talks of "shepherds keeping watch over their flock by night", but in Palestine the sheep-rearing stopped in winter. For not talking of the uncertainty about the year, because no document, apart from the Gospel, confirms the famous "census" that obliged the Holy Family to move to Bethlehem.
We are on a mythical stage.