13 Grandmother Moons of the Celtic Lunar Calendar

It’s taken me a while to get my head around the Celtic Coligny lunar calendar. My mind wants to constantly pull me back into the Gregorian calendar where everything is neat and fixed. It’s structured and rigid. So masculine!!!

The lunar calendar flows with the rhythm of the land and consciousness of creation. I’ve been so surprised at how the Gregorian way of thinking is so entrenched in my system. Or should I say was!!…
I’m releasing the ties that bind. Softening into the bosom of the feminine. Remembering the old ways and coming back into connection. There is so much disconnection in the world right now and for me returning to the lunar calendar feels like coming home.

I gently hold all of my parts in tenderness as I softly and so very gently open my heart to the wisdom I hold in my bones. Letting the illumination of the moon guide my way….

This feels so important as the 13th moon which rises roughly every 2-3 years is the embodiment of the Divine Feminine. So interesting the Gregorian calendar has erased the thirteenth moon from view, renaming it a ‘blue moon’ and treated as an extra, rather than honoured as part of Earth’s natural rhythm, one more thread cut between us and the wisdom of the old feminine cycles, further feeding the disconnection!

So here’s to the rise of the Divine Feminine, the wild, feral women, that hold the wisdom of the  medicine of the land, sky and sea. The stars glisten through her body as she runs with the wolves!!!
This new year, which in Celtic cosmology lunar calendar started at Samhain is a year of 13 moons!!!

What follows is my version of trying to make sense of the lunar calendar (haha!! See, the logical masculine mind still needing control and understanding, instead of just feeling and being with the moon as she moves through her cycles!!)

The Coligny Calendar...

The Coligny Calendar is an ancient Celtic lunar calendar that was discovered in Coligny, France, in 1897, on a bronze tablet dating to the 2nd century AD, This artifact provides insight into the sophisticated lunisolar system employed by the Celts. It is considered one of the most important surviving examples of early Celtic timekeeping and offers valuable insight into the Celts' understanding of time, the moon's cycles, and their agricultural and religious practices.
The Coligny Calendar spans 62 lunar months, divided into two segments of 31 months each. These 31-month blocks may correspond to longer seasonal or agricultural periods. The calendar is primarily lunar, based on the moon’s phases, but it also integrates elements of the solar cycle to keep the months aligned with the seasons.. The lunar year is made up of 12 to13 months, each of which begins at the new moon. The months are grouped into seasons, and the calendar reflects the cyclical nature of life, with special attention to important agricultural markers like sowing, harvesting, as well as being tied to ancient Celtic holidays such as Samhain, Imbolc, Beltane, and Lughnasadh. Which fall on the 2nd new moon after the Solstice/Equinox.

The Coligny Calendar stands as an exceptional example of Celtic calendrical systems, blending both lunar and solar cycles in a way that helped organise not only the agricultural life of the Celts but also their spiritual practices. Though much remains unknown about the exact cultural practices tied to the calendar, it serves as a key artefact  for understanding how the Celts marked the passage of time and the rhythms of nature.

The Coligny Calendar also features an intercalary month (a 13th month) which rises every 2-3 years. This intercalary moon does not belong to the ordinary counting of time. It stands apart, an in-between month, holding the year steady so that seasonal rites remain rooted in land, light, and harvest. Such a moon carries a liminal quality, a pause in the rhythm where endings could soften and something new could quietly gather.
The Moon does not move in tidy weeks. Her months lengthen and shorten, breathing between twenty-nine and thirty days, refusing the straight lines of counting, but rather following her own rhythm. Time was once kept by watching the sky, not the fixed Gregorian calendar that we now are so used to and in many ways bound to. So we let go of our attachment to fixed months and each Full Moon is honoured as the natural progression regardless of the calendar month. When an extra moon arose, it was held apart as a natural threshold.

The Celtic year was anchored to seasonal portals, with Samhain marking the great turning, the dying of the old year and the opening into the new year, the dark half. When a 13 moon arose it would be honoured as the intercalary moon before Samhain, acting as a holding vessel, a pause that kept the festival aligned with the thinning of the veil, the waning of light, the falling leaves, and the descent into winter. This 13th moon did not belong fully to the old year or the new. It hovered at the threshold, a moon of suspension.

The 13th moon is a crucial tool for keeping time in harmony with the natural world, a testament to the Celtic peoples advanced understanding of astronomy and natural rhythms. Some say the 13th moon is an ‘extra' moon, but I don’t see it as that. Again the ‘extra’ only comes into play if were looking at it from the Gregorian prospective. Instead, I see it as a subtle reminder that time is not rigid, but fluid, and when the 13th moon rises its a reminder to pause, soften into stillness and to move with creations currents. The 13th moon follows her own rhythm, which is felt as liminal time, a pause in the turning, much like the ‘a year and a day’ that Celtic peoples honour. Seen as a complete initiatory cycle, one that allows time not only to turn, but to settle. It is time plus integration, held within the surplus of time that invites deeper listening. When the 13th moon appears in the year, it is not fixed, but felt. It marks time that has slipped free of counting, a liminal span when the Sun and Moon (masculine and feminine ) are brought back into harmony. Such moons belong to ancestors, to gestation, and to the unseen work of becoming. Honouring the cycles of nature and the turning of the year. In this rhythm, the lunar months guided ritual, sowing, harvest, and reflection, each moon a threshold to pause, to observe, and to step into the next phase of life.

Imagine our ancient ancestors, those who lived and breathed the rhythm and cycles of nature. The moon would have been a loving, constant presence, that would have guided our loved ones. So it makes sense to me that the Celts followed a 13 moon calendar. Many sacred Celtic sites, like Newgrange for example, are aligned with both solar and lunar cycles. These places might have been used to track the 13 lunar cycles or marked specific points where the sun and moon intersected in their cycles. The Celts also had an intricate relationship with time, especially through their Wheel of the Year, which is based on solar and lunar cycles. The Celts celebrated key points of the solar year, such as the solstices, equinoxes, and in more recent times the cross-quarter days (Samhain, Imbolc, Beltane, and Lughnasadh)

The moon in Celtic tradition is often associated with femininity, cycles, intuition and mystery. The full moon has a deep connection with the feminine, wisdom, and the cycles of birth, death, and rebirth. The 13 moons can be seen as a journey through a passage of time, mirroring the seasons, growth cycles, and life stages. Each moon marks a specific moment of transition or energy, offering wisdom for personal growth, spiritual insight, and connection to the natural world. The lunar calendar is a powerful timekeeper, guiding nature's rhythms and ancient festivals.

The Celtic New Year begins at Samhain, when we really start to feel the descent into the darkening. The dark of the womb, the cauldron, where new life is created. The liminal space and time when the veils between worlds grows thin, and the old cycle releases its hold. Some attune the New Year to the first New Moon after Samhain, seeing it as a time of seeding, descent, and gestation, the quiet darkness from which the year’s new beginnings will emerge. Others work with the first Full Moon after Samhain, known as the Mourning Moon, a time for reflection, release, and honouring what has passed. Again here I’m going with the flow, as the moon moves and transitions each cycle, for me the new year begins with whichever moon, full or new, rises closest after Samhain.
Whether new or full, the moon’s presence serves as a guide, reminding us that the turning of the year is not only measured in days, but in the rhythms of the earth, the cycles of light and dark, and the inner journey of the soul. Samhain marks a threshold, a doorway between endings and beginnings, where we honour what has been, and prepare to step into what is yet to come.
Thirteen has long been associated with the Divine Feminine. It mirrors the Moon’s turning, the cycles of the body, and the gestational arc of life itself. Where twelve completes the visible pattern, thirteen returns us to the womb, to the dark where wisdom gathers and renewal is conceived. Women, midwives, keeners, wise women, and seers, were keepers of the thresholds, tending birth and death rites, healing knowledge, seasonal timing, and dreamwork. Their work unfolds in liminal time, where life is held rather than driven. The thirteenth moon carries this same quality, echoing the medicine of the cauldron: a vessel of containment where endings dissolve and new life is quietly brewed. Thirteen is not about the masculine energy of action, but about the feminine holding, transition, and listening to what is forming in the dark.
So the thirteenth moon becomes a threshold, time held in the cauldron, inviting listening, integration, and the wisdom that arises when the usual order loosens and life is allowed to re-balance itself.

Whether new or full, the moon’s presence serves as a guide, reminding us that the turning of the year is not only measured in days, but in the rhythms of the earth, the cycles of light and dark, and the inner journey of the soul. Samhain marks a threshold, a doorway between endings and beginnings, where we honour what has been, and prepare to step into what is yet to come.

To give the logical brain grounding presence I’ve included the Gregorian dates and months…

This year is a 13 month year!!!
New yeah starts at Samhain 2025
Celtic Full Moons: Oct 2025 – Oct 2026 (UK)....

1. 5 November – Mourning Moon
2. 4 December – Long Night Moon
3. 3 January 2026 – Wolf Moon
4. 1 February – Quickening Moon
5. 3 March – Worm Moon
6. 2 April – Hare Moon
7. 1 May – Flower Moon
8. 31 May – Blooming Moon
9. 30 June – Honey Moon
10. 29 July – Mead Moon
11. 28 August – Hazel Moon
12. 26 September – Harvest Moon
13. 26 October – Hunter’s Moon

So much love and infinite blessings from within the rays of the moon...
Theresa