First the year was divided into two halves: a dark half, with long nights and short days, and a light half, with short nights and long days. This division of time was thus equinoctial. The dates were fixed in respect to the Full Moon following the equinox if this event did not coincide with the Full Moon.
Logically, this lunar and solar system would have to include periodical corrections or embolismic (intercalary) months every now and then would have had to be made every two and a half years, excepting the thirty years period (Celtic century). This adjustment was made closer to the equinoxes, in change of great season that could include up to six or seven lunations.
The Dark Half was called Giiemorotlio for "sprouting cycle". The year was made to start in fall around November, this was the Celtic month of Samonios. A pun could be made with the name of this lunar month. The Druids, much like the other Vedic Seers were pundit punsters! Samonios being the season for the fall of leaves and seeds, a play on words could be made with Samon and Semon for "seed".
New Year's Eve was called Uegilia Samoni and was an evening celebration commemorating the ancestral spirits and souls of the deceased.
It survived in Christian lore as Halloween or All-Saints-Day. Much can be added on this time of preparations for the winter season of sleep and rest but let us move on to the "Light Season".
Semorotlio the Light season was for the "cycle of seeding". This is the season for renewal after winter's end. Spring being the period that started the warm and light part of the year.
The Celtic sidereal 24 sign system was called Prinnios from the Gaulish term Prennes for "trees". It was quite different from the Greek system (tropical) just featuring animals. The Greek Zodiac was a simplified 12 sign solar version of an ancient Vedic model involving the beasts as the fast moving Sun (active), catching up to the slower Planets as it moves through the forest of constellations (trees = passive).
The Moon draws sap up the trees, ordering life, while the Sun activates the animalistic inner fires. In this celestial forest resided godly beings. These gods who dwelt in the stars, had birds carry their thoughts from the astral forest domains, down to Earth. So far for most of the Ancients, the Sky was seen as an inverted bowl and the Earth as a plate floating in a bowl of water. The Druids knew that the Earth was spherical and had even reached a close estimate of its size: for them, the sky was thus not just one bowl but two inverted spheres being seamed together at the equator.
Sonnocinxs was the Sun-path seen as the ecliptic line traced alternatively in above and below the two hemispheres.
Now, to complete this, the two half-year seasons were broken down into two more halves, giving us the four seasons or "fourths".
1. Cengiamos was for fall, it stood for Cen (before) and Giamos (winter).
2. Giamorotio was for winter, it stood for Giiemorotlio, the Old Celtic name for winter. It evolved into Giamos, which is close to the Latin Hiems and Greek Kheimon.
3. Uesara was for spring, related to the Latin Uer and not that closely related to the Gaelic word Earrach (from Uesracos).
4. Samorotio, with the shorter Samos, was for summer, yielding the Gaelic word Samhradh, the Welsh Haf and Breton Hanv.
In monthly time there were two ways of measuring the Moon's revolutions, one was the synodic month, and the other the sidereal month. "The Synodic month is the interval of time between two consecutive new Moons, or two consecutive Full Moons. It lasts for 29.53 days - or to be exact, 29 days, 12 hours, 44 minutes, and 2.78 seconds.
Astronomers base this definition on an alignment of the Sun, Earth, and Moon, or rather, the interval between two such successive alignments. The synodic month is also known as the lunar month. The sidereal month is the period of time elapsed between two consecutive times that the Earth and the Moon are in line with the same fixed star. The sidereal month, or star month, is shorter than the synodic month. Its period is 27.32 days, or 27 days, 7 hours 43 minutes, and 11.47 seconds. The synodic month is longer because as the Moon goes around the Earth, the Earth continues to revolve around the Sun.
The Moon must travel a little further before the three bodies are in line again." It is in this manner, that we should view the complex and intricate workings of the dual systems, both lunar and solar. The Celtic week was of 15 to 14 days. The week of 7 days was not in use in the Celtic lands before its introduction by the Romans. This Semitic concept, probably of Egyptian origin, was ignored by the Celtic peoples before it was imposed through christianising.
Nevertheless, it is also possible that the Druids divided the half-month, as did the Romans, with the 6 first days of the month qualified as Uegiliai, a novena, Noiolatis, of nine days, and the 14 or 15 other days qualified as Atenouxtio.
Therefore, the month was divided into two halves (Full Moon - New Moon), in turn divided into periods of six, nine, and fourteen or fifteen days. This is good for the synodic month of 29.53 days which should not be confused with the astrological sidereal month of 27.32 days. The division of days from 6 to 9 periods in a month of 30/29 days follows the ancient Italo-Celtic liturgical calendar. In short, the month starts with the Calendae (from calare, ‘to call’) or Uegilia in Celtic (Ueilia in Gaulish, Féil in Irish, Gwyl in Welsh, Goel in Breton and Gaule/Goule in Old French, cognates of the Latin Vigilia), the Nonae, Noiolates, follows with the month ending with the Atenouxtio, or period of ‘renewal’, the waxing period.
The ninth day (Nundinae in Latin and Nametolatis in Celtic) was a day of rest and meeting time for family and friends. Other days of rest were the inauspicious Anmata days. The Anmata, “Non-even”, days were not necessarily considered as a sign of bad omen. Each day was given a runic or oghamic letter of the Bobileth or BethLuis-Nion. If one is to follow the Germanic calendar, one will discover an old I.E. procedure used by the Vedic Brahmans and Celtic Druids, that is, a reckoning of the Moon phases to tabulate dates that would otherwise be approximate. This of course is to prevent major shifts in the Lunar-solar time clocks.
The Teutonic month (Maenopiz) was also divided into 30 or 29 parts. But unlike the Celtic system which comprised of six 30 day’s months and five 29 day’s months, the runic day’s months were more at random with only one floating 29 or 30 day’s month. It seems that adjustments were performed on the advent of the Full Moon. Much like the Celtic Moon calendar, it also had two embolismic months: Lida and the coupling of Yul. These were planned according to the number of Full Moons between solstices making it possible for them to be inserted at some time of the year other than the usual Celtic order of Ciallobuis Sonnocingos and the doubling of Samonios or MIDX.
Tabulation of the monthly days was performed with the aid of the runic and Coelbreni alphabets. Each day in the Teutonic month was represented by a matching rune to the number of 29 to 30 for the entire month. The Celtic order comprised of 14 to 15 signs in all and repeated for Atenoux New Moon starting on the New Moon. The origins of this system which are lost somewhere in the mist of time point out in the direction of the Danubian Culture ca 5000-3800 BCE.
The recording of the lunar events of the year was called Amserolenmen in Old-Celtic, and Allmonaxta in Old-Germanic. The luminaries, Sun, and Moon in their monthly progression, cross the many constellations of the Zodiac.
These were likened to a forest of trees called Prinnioi (pl.) or Prinnios, the word for "wood", "divining" and "destiny". It should be clear by now, that the Almanac or Amserolenmen was the catalogue of lunar events and that the Zodiac or Prinnios was the recording of solar events. The lunar year was called Blidnis by the old Druids, and it was based on 12 lunations called Reuia. There is an easy bardic pun to be made with this term and the word Reuesia, for open clearing or cleared unwooded area. The Old Celtic vocabulary pertaining to the Moon is very rich and diversified. The Moon had many names; Diuon and Reui for the luminary, and according to the inscriptions found on the Coligny Calendar; Luxsna, which is much like the Latin name Lûna. Leucara means the "lighteous" and later evolved into Lugra, or the Welsh name Lloer, and Loer in Breton. As for the Gaelic terms, rich in periphrases, we have Eidsciia for the phases (pl. neuter), whence the Gaelic masculine form Easca.
Source: The Calendar and Almonach of the Ancient Druids By Michel-Gérald Boutet, 2001
Image: Celtic Tree Calendar following the lunar cycle via Ireland Calling