Despite the popularity of the Celtic Tree Calendar, there is no historical evidence that anything like it was used by the ancient Celtic peoples; in fact it was an invention of Robert Graves (1895-1985), an English Celticist, poet and critic. The Ogham, which is used in this modern day calendar, was once an ancient writing system that represented the sounds of primitive Irish and Old Irish. Examples of Ogham can be found carved on hundreds of stones in Ireland, Wales, Scotland, Devon and Cornwall. Due to the difficulty of carbon dating stone, archaeologists have cautiously dated the Ogham to the late 4th century AD. Ogham stones were used to record Gaelic Irish tribal and family names as well as, on rare occasions, deity names such as the god Lugh and are believed to have been grave markers or boundary stones.
During the Medieval Period, the Ogham letters were translated into tree names, although not all of the letters have a direct meaning of a tree. Early Christian missionaries used the Ogham alongside Latin. There is no historical evidence of the Ogham being used for divination, but there are obscure mentions of Ogham in early Irish sagas and legends that may suggest a magical use of this alphabet.
The oldest Celtic calendar was discovered buried in a French vineyard in 1897 in the town of Coligny. The highly complex system, with an error of only one day in 455 years, was found broken into 149 pieces and is believed to have been the work of Druid astronomers and mathematicians wanting to safeguard their festivals and customs at the time when the Julian Calendar was being introduced by the Romans. A life-sized statue of what is believed to be the god Mars or even the Celtic god Lugh, as he was holding a spear, was also found broken along with the calendar.
Christian Souchon, whose website I have linked below, believes that the statue and calendar were destroyed during an attack led by Chrocus (260-306 AD), a leader of the Germanic tribe called the Alamanni. Chrocus and his men are known to have destroyed many ancient temples across Gaul. Chrocus also supported Constantine’s claim to become emperor. Constantine I was the first Roman emperor to convert to Christianity.
The Coligny Calendar, as it is known, has been dated to around the first century AD. Spanning a period of five years, it is possible that the calendar was once displayed inside a temple. The Druids followed a thirty two year calendar made up of five cycles of sixty two lunations and one cycle of sixty one lunations. Diodorus Siculus, a Greek historian living in the 1st century BC, noted that the Celtic peoples living on the continent held sacrifices every five years.Â
Made from a bronze panel, this lunisolar calendar is divided into sixteen columns, each of which is divided into four months except for the fifth and ninth columns, which contain two lunar months. Two intercalary months have been added to the calendar to align the solar year with the lunar year. Each intercalary month has thirty days and was added every two and a half years. In other words, the addition of a thirteenth moon. A standard Celtic lunar year had twelve months consisting of 355 days. The sun was used to calculate when a thirteenth moon needed to be added.
The Metonic Cycle was also used to keep track of time. This is where the moon returns to exactly the same place with exactly the same moon phase every nineteen years. The Stones of Stenness on the Isle of Orkney and the Callanish Stones on the Isle of Lewis, Scotland were constructed around 5,000 years ago and both align with the Metonic Cycle. The kerbstones at Knowth near Newgrange, Ireland have symbols engraved on them that are believed to be sophisticated calendars that are one thousand years older than Stonehenge. It is very possible that the knowledge contained on the Coligny Calendar was passed down by the Neolithic and Bronze Age peoples that built and carved these stone structures as well as the famous golden cones.
Each month, which was a full lunar cycle on the Coligny Calendar, was divided in half by the word ‘atenoux’ which is thought to mean something similar to ‘returning night’. The word ‘atenoux’ may have marked the time of the last quarter moon of that lunar cycle. The first half of the month was the light half which lasted fifteen days and the second half of the month was the dark half and lasted either fourteen or fifteen days. This encompassed a lunar month with each lunar cycle waxing and waning; measuring time in fortnights.Â
The word ‘fortnight’ comes from the Old English for ‘fourteen nights’. The Old English word ‘sennight’ meaning seven nights is no longer used but an example of it can be found in the witches’ curse in Shakespeare’s Macbeth. And the Saxon word ‘den’ as in ‘Good den’ (Good Day) really meant ‘night’ or literally ‘Good Moon-Day’. The Anglo Saxons, as well as other Germanic tribes and Celtic peoples counted in nights not days as the Romans did. For the Celtic peoples, each day began at sunset just like it did for the Germanic peoples. This is evidenced with their festivals beginning on the eve, such as Bealtaine Eve. Their months began on the full moon but for the Germanic peoples the month began on the new moon.Â
Only two of the months on the Coligny Calendar have been fully reconstructed. The month called Samonios which is followed by the Celtic word for ‘good’ (MATU) and the month called Dumannios which is followed by the Celtic word for ‘bad’ (ANMATU). Months with twenty nine days were ‘anmatu’ and months with thirty days were ‘matu’. This suggests that some months were lucky while others were not. Months with twenty nine days were also called ‘divertomy’, meaning ‘without a last day’. The writing on the calendar is in Latin, but the language is Gaulish.
The first of the intercalary months, which was inserted before Samonios at the start of the first year of the calendar, was possibly called Quinonios. The written description for this month says, ‘the amount of days of the present year was raised to 385 owing to Quinonios’. The second intercalary month was called Rantaranos or Bantaranos meaning ‘the sun’s march’. The first two lines of this month’s description reads ‘Ciallos b-is sonnocingos’. Sonno means ‘sun’ and cing means ‘to run’, ' to proceed’ or ‘to go’. Rantaranos was inserted between the months of Cutios and Giamonios in year three of the calendar.Â
Due to the vagueness of the names of each of the months, some Celtic scholars such as Sir John Rhys (1840-1915) and Eoin McNeill (1867-1945) a Gaelic revivalist, did not believe that the months were aligned with the correct time of year. For example, they believed that Samonios, the first month on the Coligny Calendar, was the lunar month of the Summer Solstice and not the month of November as stated by other research. Joseph Monard who wrote ‘Histoire du Calendrier Gaulois’ published in 1999, believes that the calendar began on the Autumn Equinox.
Below, I have copied down the Gaulish/Celtic months as they appear on the Coligny Calendar along with today’s equivalent. The names that are in brackets come from Caitlin Mathews’ translations. Caitlin Mathews and her husband are both well known in the neo pagan community, teaching and writing about their own style of Celtic Shamanic spirituality.
It is curious to see that the Old Irish festivals of Imbolc, Bealtaine and Lughnasadh are not mentioned on the Coligny Calendar, only Samhain (Samonios) is.Â
The Celtic year was split into two halves: winter from the beginning of November and the month of the festival of Samhain, and summer from the beginning of May with the festival of Bealtaine. The ancient Bretons, however, had four seasons. Summer was known as ‘goanv’, winter was known as ‘hanv’, spring was ‘nevez amzer’ meaning ‘new time’ and autumn was ‘diskar amzer’ meaning ‘decay of time’.
SAMONIOS Â (October/November)
Summer’s End - The Celtic root ‘samo’ means summer.Â
Thirty days long.Â
Matu.
(Seed-Fall)
DUMANNIOS (November/December)
Possibly means ‘fumigation’ in religious rites. In mid-Irish ‘dumacha’ means ‘mist’.Â
Twenty nine days long.
Anmatu.
(The Darkest Depths)
RIUROS (December/January)
Frost. Old Irish ‘reud’ means ‘cold’. Riuros could also mean fat or plentiful. Old Irish ‘remor’ means thick, fat, stout. Welsh ‘rhef’ means thick, stout, great or large.
Thirty days long.
Matu.
(Cold-Time)Â
ANAGANTIOS (January/February)
Possibly means ‘non travelling month’. Old Irish ‘ag’ meaning ‘to go’ along with the negative prefix ‘an’.
Twenty nine days long.
Anmatu
(Stay Home Time)
OGRONIOS (February/March)
Cold Month. Celtic root ‘ougros’ means ‘cold’.
February/March.Â
Thirty days long.
Matu.
(Time Of Ice)
CUTIOS (March/April)
Unknown etymology. Possibly taken from the Greek month name for October/November; ‘Kooutios’ found in the Lokrian Calendar.
Thirty days long.
Matu.
(Time Of Winds)
GIAMONIOS (April/May)
End Of Winter. Celtic root ‘giiamo’ meaning ‘winter’. Old Irish ‘gaim’. Breton ‘goanv’. Also the name given to a year old calf (one winter old).
Twenty nine days long.
Anmatu.
(Shoots-Show).
SIMIVISONIOS/SIMIUISONNA/SEMIUISONNA (May/June)
Unknown etymology. Possibly from the Celtic ‘semi’ meaning ‘half’ and ‘ues’ meaning ‘springtime’ or feminine form of the word sun, ‘sonna’.Â
Thirty days long.Â
Matu.
(Time Of Brightness)
EQUOS (June/July)
Possibly from the Celtic root ‘ekwos’ meaning horse. Horse racing was popular at around the time of the festival of Lughnasadh.
Thirty days long. Equos had twenty eight days on year 2 and year 4 of the calendar.
Anmatu. It was the only thirty day month that was ‘unlucky’
(Horse-Time)
ELEMBIUOS/ELEMBIU (July/August)
Month Belonging to the Deer. From the Proto Indo European root ‘elen-bho’ meaning ‘deer’. This was Deer Hunting Month in the Attic Calendar. Welsh ‘elain’ and Old Irish ‘elit’ meaning doe, hind or young deer. A time of tribal gatherings, the continuation of Lughnasadh, fairs, contracts and marriages.
Twenty nine days long.
Anmatu.
(Claim-Time)Â
EDRINIOS/AEDRIOS (August/September)
Bright or Hot Month. Proto Indo European ‘aidh’ and Old Irish ‘aed’ meaning ‘fire’ or 'heat’. Claims were judged and awarded.Â
Thirty days long.
Matu
(Arbitration-Time)Â
CANTLOS (September/October)
Possibly means ‘Song Month’. Welsh ‘cathl’ and Old Irish ‘cetal’ meaning ‘song’. Bards ended their travels and settled down for the winter.
Twenty nine days long.
Anmatu.
(Song Time)Â
I hope that you enjoyed this deep dive into Celtic time keeping and in the future I will cover ancient Germanic time keeping in more detail than I have done in the past.
Brightest blessings,
Elissa
Bibliography And Online Sources
The Moon, Myth And Image by Jules Cashford (2003)
Druids by Anne Ross (2004)
The Celtic Tradition by Caitlin Mathews (1995) Does have neo-pagan elements.
Dictionary of Celtic Religion and Culture by Bernhard Maier (2000)
The Ancient Celts by Barry Cunliffe (2018)
The Celtic World edited by Miranda J. Green (1996)
irishpaganschool.com and ogham.academy (Lora O’Brien and Jon O’Sullivan)
en-academic.com
chrsouchon.free.fr