"Currently, perihelion occurs about 14 days after the December solstice, thus making January 4 the mean date of perihelion. January's perihelion puts Earth at a distance of 91,402,505 miles (147,098,074 km, 0.98328989 AU) from the Sun and July's aphelion is at 94,509,130 miles (152,097,701 km, 1.01671033 AU)"
So, the astronomical event that coincides more of less with Christmas is perihelion, the part of Earth's orbital movement closest to the Sun, culminating around the date of 4th January (in 2011 it's the 3rd of January.
How come people use to have important ritual holidays in this part of the year ever long before the official Christianity parable, dedicated to various deities over time, for example:
"It is beyond doubt that Christmas was originally a pagan festival. The time of the year and the ceremonies with which it is still celebrated, prove its origin.
Isis, the Egyptian title for the "queen of heaven," gave birth to a son at this very time, about the time of the winter solstice. The term "Yule" is the Chaldee (Babylonian) name for "infant" or "little child.""
(from: Christmas: Is it "Christian" or Pagan? Lorraine Day, M.D.http://www.goodnewsaboutgod.com/studies/holidays2.htm)
Other sources mention Baal festivities, Mithra festivities, Adonis festivities etc, but I could not find quotes right now.
Anyway, the idea that Christmas was intentionally super-positioned on pagan rituals is not new, neither the subject of my post.
The question is what astronomical event invariably takes place in this period. Maybe the ancients chose this period because of the earthly symptoms of
Anyway, over the time, some people really interfered with the calendar system. I cannot realize if this shifted some real meaningful ritual dates and made them unknown by the large public or not. Maybe the calendar needed the corrections that were made, but still these raise some questions about what are we celebrating and when.
And the parades and public festivities originate in the antic "lesser mysteries" that were taught to the public through dances and theater, or ritual shows e.g. mask-dances.