The earliest record we have of the festival of Samhain in the Celtic world comes from the Coligny Calendar, a native Celtic lunar calendar inscribed on bronze tablets and discovered in eastern France a hundred years ago. The calendar -- dated, through epigraphic evidence, to the 1st century CE -- is written in the Latin alphabet and was found in conjunction with a Roman-style statue (identified by some writers as Apollo, by others as Mars), but the language used is Gaulish and the dating system itself bears little resemblance to Roman models, implying that it represents the survival of an indigenous tradition maintained by native clergy.
A detailed discussion of the calendar lies outside the scope of this article, but for our purposes it will be enough to point out that its year consists of twelve regularly recurring months that fall naturally into two groups, one headed by the month that is labeled SAMON (for Samonios) and the other by the month GIAMON (for Giamonios), and that the names of these two months are clearly related to the terms samos "summer" and giamos "winter" (cf. Gaelic samh(radh) "summer", geamh(radh) "winter"; Welsh haf "summer", gaeaf "winter"). The date of SAMON- xvii is identified as TRINVX SAMO SINDIV, which can be readily interpreted as an abbreviation of Trinouxtion Samonii sindiu ("The three-night-period of Samonios [is] today"). This is one of the very few dates in the calendar that is given a specific name, testifying to its importance as a festival; and since Samoni- is obviously the origin of the modern name Samhain, it is reasonable to equate the Trinouxtion Samonii with the feast that is still one of the most important dates in the Celtic ritual year.
We should note, however, that since the Coligny Calendar gives no indication of how its months relate to those of the Roman calendar, we have no conclusive evidence that would allow us to fit it into the framework of our own year, and scholars are still very much divided on the issue. The most confusing element, of course, is that Samon- refers to summer, and so would naturally lead one to think that a month with that name would head the summer half of the year; and many of the earlier interpretations of the Coligny Calendar take this for granted. In living Celtic tradition, however, the festival of Samhain, despite its name, is definitely the beginning of winter. Though such evidence doesn't necessarily exclude the possibility that Continental Druids used a completely different terminology, many scholars now accept the authority of the living tradition and place the Samonios month in October/November.
What does the name of the festival mean, however? Here, again,we run into controversy. The traditional interpretation -- first put forward in the Mediaeval glossaries and still held to by native speakers -- is that it means "summer's end", being a combination of samh "summer" and fuin "ending, concealment". This is obviously a folk etymology, since we know that the earliest form of the word (Samoni-) had a different structure, but its importance to the living tradition should make us wary of dismissing it too lightly. Although philologists have been unable to find a plausible Indo-European explanation for a suffix -oni- meaning "end of" (the suffix, by the way, occurs in at least three of the other Coligny months), this is not conclusive in itself: there are quite a few other derivational suffixes attested in Old Celtic that resist an easy Indo-European etymology, although their meanings are uncontroversial. What should be kept in mind is that in the ritual context of the Celtic Year, Samhain is strongly identified with the "end" or "concealment" of Summer, the Light Half of the year. In the modern Gaelic languages the festival is called Samhain (Irish), Samhuinn (Scots Gaelic), and Sauin (Manx). The night on which it begins (Oíche Shamhna in Irish, Oidhche Shamhna in Scots Gaelic, Oie Houney in Manx) is the primary focus of the celebration. The Brythonic languages call the feast by a name meaning "first of Winter", borrowing the Latin term calenda which designates the first day of a month (Welsh Calan Gaeaf, Breton Kala-Goañv, Cornish Kalann Gwav), but the beliefs and practices associated with it are consistent with what we find in the Gaelic countries, and will help us discover a pan-Celtic theology of Samhain.
The Coligny Calendar's division of the year into two halves associated with summer and winter is still very strongly reflected in Celtic folk practice, where the yearly cycle consists of a dark half beginning on Samhain (November 1st), mirrored by a light half beginning on Bealtaine (May 1st). The rituals surrounding Samhain and Bealtaine are closely related to each other and make it clear that the two festivals are linked, but also that they deal with opposite energies within the unfolding of the year. What is explicit and active in one is implicit and dormant in the other, and vice versa.
This is often expressed as the notion that what disappears in our world at once becomes present in the Otherworld, and it has even been suggested, on this basis, that Samhain's "summery" name was originally intended to designate the beginning of an Otherworld summer! Whether this is plausible or not, it remains certain that while Samhain began one kind of yearly cycle, Bealtaine began another, and both could be construed as a kind of "New Year". In ancient Ireland the High King inaugurated the year on Samhain for his household (and, symbolically, for all the people of Ireland) with the famous ritual of Tara, but in nearby Uisneach, the sacred centre held by the druids in complementary opposition to Tara, it was on Bealtaine that the main ritual cycle was begun. In both cases sacred fires were extinguished and re-lit, though this happened at sunset on Samhain and at dawn on Bealtaine. Bealtaine was a time of opening and expansion, Samhain a time of gathering-in and shutting, and for herd-owners like the Celts this was expressed with particular vividness by the release of cattle into upland pastures on Bealtaine and their return to the safety of the byres on Samhain.
Which of these two dates, then, should we think of primarily as the "Celtic New Year"? Although both deal with the beginning of a cycle, Samhain begins it in darkness, and there is no doubt about the pre-eminence of darkness in Celtic tradition. In De Bello Gallico Julius Caesar notes that the Celts began their daily cycle with sunset (spatia omnis temporis non numero dierum, sed noctium finiunt; dies natales et mensum et annorum initia sic obseruant, ut noctem dies subsequatur -- "they define all amounts of time not by the number of days, but by the number of nights; they celebrate birthdays and the beginnings of months and years in such a way that the day is made to follow the night"), and this is confirmed by later Celtic practice. Darkness comes before light, because life appears in the darkness of the womb, all things have their beginning in the fertile chaos that is hidden from the rational mind. Thus the year begins with its dark half, holding the bright half in gestation as the seeds lie in apparent death underground, although the forces of growth are already at work in Otherworldly invisibility. The moment of death -- the passing into the concealing darkness -- is itself the first step in the renewal of life.
