The Atheist Poster now causing lots of consternation.
Seems that in various locales people (mainly Christians) are getting all bent out of shape concerning a billboard (see graphic) put up concerning this particular date: December 25th. Atheists have been accused of being "mean-spirited", "bigoted", "insane", "blasphemous"... you name it. As usual, we need to let the emotionalism and histrionics, hysteria die down and examine the Atheist case rationally.
Again, this requires going back into Church and religious history, something with which most Americans are unaccustomed to doing. They are more inclined to simply accept dates and meanings attributed as a fait accompli.
Let's begin with this fact: that in the early centuries after Christ's death there were nearly as many dates for his putative nativity as there were major churches (by which I mean branches of the main Roman Rite Church based in Rome). Thus, Christendom found itself in the ironic position of declaring the birth of the greatest spiritual icon to ever walk the planet...but they were confounded when pressed as to exactly when it transpired!
The outcome was that for several hundred years the differing Catholic Rites celebrated the nativity on different dates. For example, the Eastern Churches (which later became the Greek and Russian Orthodox) celebrated it on the Epiphany, or January 6th. Meanwhile, most Gnostics celebrated it on April 24th-25th, while other sects placed it in May. Not until 354 A.D. (354 C.E.) did the central Roman Rite Church choose December 25th as the date.
The choice may be obscure until or unless one appreciates that at the middle of the fourth century, Rome had essentially made its peace with the indigenous Christians - thanks to the Emperor Constantine (274 - 337). Recall that Constantine was the de facto head of the Sol Invictus cult for which December 25th was celebrated as "the Birthday of the Unconquered Sun".
In reality, this referred to the Winter Solstice, or that date in the year when the Sun was at its maximum declination below the celestial equator (now calculated to be at -23.5 degrees). At the same time, it was the date at which the Sun would begin its journey back north along the ecliptic to meet the celestial equator by the time of the Vernal (Spring) equinox. This northward march meant geometrically longer diurnal circles, hence the winter solstice marked the astronomical date when days began getting longer - hence a solar "re-birth" in a manner of speaking. Though true, we now compute the Winter solstice on Dec. 20th or 21st (this year it coincided with a lunar eclipse - the first since 1638), at that time ca. 4th century, Dec. 25th was the best they could manage and +/- 4-5 days possible error was damned good given their level of measurement.
In effect, by selecting December 25th as the nativity of Christ, the Church repaid Constantine for his generosity (via the "Edict of Milan" issued in 313, which not only permitted Christians the freedom of religious worship and their religion's recognition by the State, but also reparations for previous losses, such as having property confiscated). In other words, the choice sealed a continued basis for accommodation and cooperation between Rome and Christianity and also empowered the latter - providing the impetus to become the religion of the then civilized world.
Less well known, is that the ancient religion of Mithraism was also well-entrenched in Rome by the time of the Christian choice of December 25th, and indeed, they (Mithraists) also celebrated that date as the nativity of the Lord Mithra. Religious historian Joseph McCabe (American Atheist Magazine, Nov.-Dec., 2007, p. 8) notes that "Mithra was an old Aryan Sun-god".
After the Persians conquered and blended with the Babylonians, Mithraism spread and probably ended up in Rome early in the 2nd century via conquered slaves.
At this point some confusion resides, as some ancient religious historians believe that the Mithraic deity and Mithraism were apart from the Sol Invictus cult, while others believe they were the same. My studies lean to separate entities with the Sol Invictus the official (native) Sun god of the later Roman empire- having been created by Aurelian in 274. Aurelian made it an official cult alongside the traditional Roman cults. Even here many scholars disagree whether the new deity was a refoundation of the ancient Latin cult of Sol, a revival of the cult of Elagabalus or completely new. But these scholars DO concur it had nothing to do with the Mithraic Aryan Sun god, or Lord Mithra (who appears more likely to have been one of the first imaginary "divine men" invented, as opposed to just a solar identity).
The gist of it all is that multiple cults or religions flocked to December 25th as the putative nativity of their deity- and that included the Roman Rite Catholic Christians (for Jesus), the Mithraists, for Mithra, and the Sol Invictus cult for Sol Invictus (the 'all-conquering Sun').
The other point here is that the Christians flocked to the pagan designated date of December 25th, they did not have a unique date of their own.
In this respect, the Atheists are quite correct and December 25th does not exist as any uniquely holy date, hence for all intents is a myth. In this sense, "myth" means: an unproved collective belief that's used to justify a social institution. If one therefore is going to celebrate a nativity - he should (for history's sake) go the whole hog and celebrate it not only for Yeshua, but the Lord Mithra, as well as the Roman god, Sol Invictus. They all share that date, and all are entitled to acknowledgement.
For Atheists, the issue is elementary: they simply acknowledge the date as that coinciding with the ancient Winter Solstice and mark it purely as an astronomical event. Yes, socially we may well celebrate with family and friends and even give presents, but this is part of a recognized habit or custom. Heck, I even sent my fundie bro - Pastor Mike - a little gift which I do hope he will cherish and use to enhance and refine his religious sensibilities!