Where does the Coligny calendar sit in the year?
And throwing light on the story of St Patrick and King Loegaire lighting ritual fires at Easter
Happy Spring Equinox and Easter to everyone (well at least those of you in the north)! This week I’ve had a new paper published “Identifying the Seasonal Placement of the Coligny Calendar” in Etudes Celtiques. Which is very exciting – and I confess a fair bit nerve-wracking – for me.
This is the most consequential paper I will write about the calendar. It lays out how the calendar is placed in the year, by using particular notations that are unique and don’t just follow a general monthly pattern, and by expecting that all these points when taken together should sit at significant and identifiable points in the year, such as the solstices and equinoxes. Fortunately, there is only one layout that fits all the points. So, this analysis tells us how the Celts all over western Europe and the Isles, including the Picts, conceived of time, how they counted it, and organised around it. And this time, we’re not just guesstimating or making assumptions, this time – finally – we have the ancient pagan Gauls giving us a mathematically precise solution.
For those of you with access to a university library you should be able to get a copy soon, everyone else will have to wait the prerequisite two years for it to be put in the public domain. But then, as we’ve waited through 140 years of research into the calendar, I guess we can wait a wee bit longer.
I do expect some pushback. For some reason this topic is quite emotional for a lot of people, and over the last few centuries a number of ideas have become popular, some of which turn out to be valid, but some not. Like the idea that Samhain starts the Celtic year – which it doesn’t, or that the Celts counted from the dark times of the day, month and year – which they don’t, they only counted the day from sunset just as most of their neighbours did, nothing more. Or that their lunar month started with the full moon, which it doesn’t. Or that the notation TRINUX SAMONI refers to three days of Samhain - which it doesn’t.
From the moment I started working with the Coligny calendar, the only question people kept on asking me was – how does the Celtic year fit with the yearly cycle? And from this the related questions - How did they organise their festivals? Where does the Celtic year start? And so on. For a long time I brushed off these questions, because the way to solve a really big problem is to first identify the elements of that problem, find the data, analyse the data, understand that data and all its interactions – of which there are roughly 50,000 on the calendar. It’s a massive web of different notations, all with their own patterns, and all interacting with the other notations in a crazy, wonderful, mathematically mesmerising dance.
So I started from scratch. I took each notation, analysed its patterns, then compared my solution to other researchers’ solutions, discovering any discrepancies, analysing the differences, adjusting, testing, and re-testing, because this method not only provides a valid data set, but it also uncovers how researchers are conceptualising these issues. A lot of work had been done by previous researchers, but as time went on, I stood on their shoulders and added to the body of knowledge.
I’ve published three papers in this process, the first1 was to solve the most difficult and trying question of the accuracy of the calendar, to show that this calendar was indeed as early researchers had been sure it must, a beautifully accurate lunar calendar that kept each month in phase with the moon, and an extraordinary solar calendar using the Metonic cycle, with a variable day to keep in sync with the month and year forever.
The Coligny calendar is the most accurate, complex, and utterly beautiful luni-solar calendar ever created by mankind.
The second paper2 resolved the pattern of the ‘triple marks’, a complex web that is keyed to the fortunate and neutral lunar months over the 30-month intercalary period. The ‘triple marks’ divide the daylight hours into three periods – just as Irish stories describe.
The third3 paper was consequently able to resolve how the notation patterns of the intercalary months were created by a complicated system of copying notations throughout the 30-month intercalary period. A wonderful picture of the ‘borrowed days’ of Celtic lore.
I have to admit, I loved doing this work, I find it intensely satisfying. Especially when I am dealing with an actual historical problem whose resolution holds promises of access to crucial information.
And especially when it turns out that this amazing calendar reflects a beautiful mathematical sense that the Celts employed, often ideas that are alien to our thinking today. For instance, the most important point is neither the start or end of a sequence but the midpoint. Take for example the full moon. Historical events and folklore frequently tell us that the full moon was viewed as critical to the Celts – and it is, the calendar makes that quite clear as many notations focus and dance around this point in the month. But the full moon is in the middle of the first fortnight of the month – not the start of the month, and not the end, as we’d expect of a counting sequence today, but in the centre.
The calendar’s astronomy is also exceptional. Well the ancient commentators did tell us that the Celts were exceptional astronomers and mathematicians, and the calendar backs that up in a big way. Take for example the new moon – another point in the lunar cycle that the Celts and many other cultures view as a significant point in time. The new moon is just momentarily visible near the horizon, so spotting it (and declaring the event if that culture started their lunar month at that point) was always problematic, with weather and topography often thwarting the attempt. But the astronomy of the Celtic calendar doesn’t use unreliable ‘sightings’ but is calculated to the precise moment, because the whole lunar phasing is precisely configured. Stars too are marked for their rising with the sun, not relying on someone spotting a fleeting helical rising. Lunar months are organised to keep in sync with the phase of the moon with a tolerance of less than a day – forever. The whole notion of time has been lain out with mathematical precision and wizardry. Every insight is a joy and a wonder.
The calendar starts with the equivalent festival of Beltane, positioned at precisely a lunar month before the summer solstice. It also has other key points, like the full moon at the winter solstice. And that’s just the start of a cascade of wonderful revelations about Celtic time-keeping.
Placing the Celtic calendar into the year is just cracking the door open to all sorts of amazing surprises. It tells us how the festivals are organised, how long they were, what dates they were, and how many there were. It tells us what the Celts considered to be the most exceptional points in time, such as the full moon at the winter solstice. It tells us about the astronomy and philosophy and mathematics and organisational skills that all contributed to this magnificent and unparalleled piece of science.
But today, because it’s Easter, I’d like to tell you the story of St Patrick lighting his Pascal fire in defiance of the Irish king and all his elite who were gathered to perform rituals on the Hill of Tara, the Feis of Tara, on what one author called the ‘easter of the pagans’.
This is the story as found in Muirchú's 7th century Life of St Patrick:
It so happened in that year that a feast of pagan worship was being held, which the pagans used to celebrate with many incantations and magic rites and other superstitious acts of idolatry. There assembled the kings, satraps, leaders, princes, and the nobles of the people; furthermore, the druids, the fortune-tellers, and the inventors and teachers of every craft and every skill were also summoned to king Loegaire at Tara, their Babylon, as they had been summoned at one time to Nabuchodonosor, and they held and celebrated their pagan feast on the same night on which holy Patrick celebrated Easter. They also had a custom, which was announced to all publicly, that whosoever, in any district, whether far or near, should have lit a fire on that night before it was lit in the king's house, that is, in the palace of Tara, would have forfeited his life. Holy Patrick, then, celebrating Holy Easter, kindled the divine fire with its bright light and blessed it, and it shone in the night and was seen by almost all the people who lived in the plain.
For centuries now people have argued about this story. Is it an entirely fanciful religious tale of how Christianity claimed the souls of Ireland? And, was there ever really a special pagan ritual day at the same time as the Christian Easter?
Well the calendar tells us the answer is yes, there was. Not only that, it was one of the three most important days of the Celtic year. A day of magic and ritual.
Easter from very early days in the church is calculated as the Sunday after the full moon of the Spring Equinox (and all the various rifts and arguments were largely about how to exactly define the precise timing of each of these events). So Easter is a luni-solar date. And the Celtic calendar is also luni-solar, and its special day was on the full moon of the spring equinox. So the two dates could easily have fallen together if Sunday occurred within the 24 hours of the full moon – which it will frequently do.
Sometimes, history really is stranger and far more extraordinary than fiction. And not everything we are told can be dismissed as fanciful nonsense.
So Happy Equinox again, hope the spring puts a little happiness into your life! From the depth of cold dank winter eventually comes the light and warmth once more. Well done sun, well done moon!
The Coligny calendar as a Metonic lunar calendar, Etudes Celtiques 42, 2016, p95-122 https://www.persee.fr/doc/ecelt_0373-1928_2016_num_42_1_2471
Defining the systematic patterns for the triple marks of the Coligny calendar, Etudes Celtiques 44, 2018, p91-118 https://www.persee.fr/doc/ecelt_0373-1928_2018_num_44_1_2182
Building the intercalary months of the Coligny Calendar Etudes Celtiques 48, 2023, p55-78 https://www.cnrseditions.fr/catalogue/revues/etudes-celtiques-48/
Thank you, this is awesome. One thing I have been wondering, Helen. Do you ever transpose for the Southern Hemisphere or do you leave it with the Northern names? I realise you are in Australia; I am in NZ and have been wondering about this one!