As societies moved from from from per-historic to complex civilizations their calendar system adopted from nature and weather calendars to direct observation and lastly to calculated calendars (see here). In this transitions, the switch from lunar calendars to solar calendars (pure solar, lunar-solar or solar-lunar) was an important step seen in many cultures but most prominent in Egypt history which has spaned (or spawned) over 3000 years. The famous myth of Isis and Osiris written down by the Greek Plutarch shows a correspondence to the cultural shift from matriarchal to patriarchal society with complexer ritualized spirituality and civil administration. Isis prevails to a certain degree, making even a revival in Roman times and I would say in Christianity (see Isis, Mithras and Jesus: Clash of male and female Archetypes in classical Rome). Plutarch’s story of the fight between sun and moon, good and evil, yin and yang, based on Egyptian oral teachings  has beneath its astronomical setting psychoanalytical and sociological dimension.

The Egyptian civil calendar, base of the Roman Julian and today’s Gregorian calendar, was the first  solar calendar known to use a year of 365 days, approximately equal to the tropical year. The Egyptians added 5 days to the schematic (astronomical) year of 30 x 12 = 360 days, invented by the Sumerians around 2400 B.C. to get a solar year. Epigone was the five days of holiday they set in to even the year before New Year. The Greek word means “born afterwards”. The Sumerians had also holidays and called them “sleepers days”. 

The 360 days Sumerians (Chaldean) normal year equals with the 360 degrees of the epileptic divided by 12 sectors, the latter again unchanged until today. This astronomical calendar could be connected to the Sumerian civil lunar year of 354 days. On a side note, the Mesopotamians used also the first mathematical position system i.e, an sexgesimal arithmetic, which is method of comutation  by 360 of the full circle divided by 12 hours in 60 minutes and60 seconds and came up with weeks and months. Those numbers 5,7, 12, 60 were meaningful and sacred (some sources say also six, but it disturbes my sense of arithmetic):

• Seven that is 5 visible planets to the sumerians plus (2) sun and moon.
• Twelve, Jupiter completing a full cycle through the epileptic in twelve years
  
• 60 years for 5 full Jupiter and 2 full Saturn  cycles the epileptic (5 and 2 again give 7); 5 times 12 of course giving 60, 360and in a way six.
  

Back to Egypt, they simultaneously maintained the older lunar calendar, which  consisted of twelve months whose duration differed according to the length of a full lunar cycle (normally 28 or 29 days). Each lunar month began with the first visible new moon. Since the lunar calendar was 10 or 11 days shorter than the solar year, a 13th month (called Thoth) was intercalated every several years to keep the lunar calendar in rough correspondence with the agricultural seasons and their feasts. New Year’s Day was signaled by the annual heliacal rising of the star Sothis (Sirius), when it could be observed on the eastern horizon just before dawn in midsummer; the timing of this observation would determine whether or not the intercalary month would be employed. However, the new calculated solar calender with 365 days matched the tropical years and seasons much better, and here is the story of  how the additional five days were found:

The following text an excerpt and translation based on a old narrative in German of Plutarch’s work found in the book of  Dr. Wiedemann, Muenster 1890. It can can be seen another myth, but to me there is much more in it: an astronomical revolution. Plutarch’s full text can be obtained in English: Part One of Plutarch’s Greek work entitled Moralia, which was published in Volume V of the Loeb Classical Library, 1936 edition (now in public domain).

This Part One is entitled Isis and Osiris and the extract includes Plutarch’s version of the entire myth of the death and subsequent resurrection of the Egyptian god Osiris.  This version is the only relatively complete telling of this story that has survived down to the modern era, although all parts have found as piecemeal in Egyptian writings.

Chronus (Geb , the god of the earth) and Rhea (Nut, the goddess of the night sky) angered the sun god Helios, their grandfather, because they were locked in a perpetual embrace thought to be in a constant state of love making. Helios (Ra), when he became aware of Rhea’s (Nut’s) intercourse with Chronus, invoked a curse upon her that she should not give birth to a child in any month or year; however Hermes (Toth), also being enamored of the goddess, helped her out and she gave later birth to five gods.

Playing checkers with Selene (Goddess of the moon and and sister of the sun-god Helios), he won from her the seventieth part of each of her periods of illumination, and from all the winnings he composed five days, and inserted them as an addition to the three hundred and sixty days (12 x 30). The Egyptians intercalated these five days and celebrated them as the birthdays of the gods. Called Epigone, those days of holidays were set in to adjust to the solar (tropical) year before New Year. The Greek word means “born afterwards” when 5 days was added to 12 x 30 = 360 to even a year. The Sumerians had also those holidays. So the lunar year became a solar year  and Nut a chance to give birth to Osiris, Horus the Elder, Set (or Seth), Isis and Nephthys. Since Plutarch used Greek names for gods and goddess an explanation and name mapping is given in the Appendix.

They relate that on the first of these days Osiris was born, and at the hour of his birth a voice proclaim with a loud voice that a mighty and beneficent king, Osiris, had been born; and for this Cronus entrusted to him the child Osiris, which he brought up. It is in his honor that the festival of Pamylia is celebrated, a festival which resembles the phallic processions. On the second of these days Arueris was born whom they call Apollo, and some call him also the elder Horus.
On the third day Typhon was born, but not in due season or manner, but with a blow he broke through his mother’s side and leapt forth.
On the fourth day Isis was born in the regions that are ever moist; and on the fifth Nephthys, to whom they give the name of Finality and the name of Aphroditê, and some also the name of Victory.

There is also a tradition that Osiris and Arueris were fathered from Helios, Isis from Hermes, and Typhon and Nephthys from Cronus.
For this reason the kings considered the third of the intercalated days as inauspicious. Nephthys became the unhappy wife of Typhon; Isis and Osiris were enamored of each other and even consorted together in the darkness of the womb before their birth and so Arueris (Horus the Elder) came from this union who was called Apollo by the Greeks.

One of the first acts related of Osiris in his reign was to deliver the Egyptians from their destitute and brutish manner of living. This he did by showing them the fruits of cultivation, by giving them laws, and by teaching them to honor the gods. Later he traveled over the whole earth civilizing it without the slightest need of arms, but most of the peoples he won over to his way by the charm of his persuasive discourse combined with song and all manner of music. Hence the Greeks came to identify him with Dionysus.

During his absence the tradition is that Typhon attempted nothing revolutionary because Isis, who was in control, was vigilant and alert; but when he returned home Typhon contrived a treacherous plot against him and formed a group of conspirators seventy-two in number and Aso, a queen from Ethiopia who was there at the time and whose name they report as Aso. Typhon, having secretly measured Osiris’s body and having made ready a beautiful chest.  Typhon jestingly promised to give it to the man who should find the chest to be exactly his length when he lay down in it. They all tried it in turn, but no one fitted it; then Osiris got into it and lay down. The plotters ran to it and slammed down the lid, which they fastened by nails. Then they carried the chest to the river and sent it on its way to the sea through the Tanitic Mouth. Wherefore the Egyptians even to this day name this mouth the hateful and execrable.

The date on which this deed was done was the seventeenth day of Athyr, when the sun passes through Scorpion, and in the twenty-eighth year of the reign of Osiris; but some say that these are the years of his life and not of his reign.

Isis, when the news reached her, at once put on a garment of mourning and wandered everywhere at her wits’ end; Isis, learning that Osiris in his love had consorted with her sister Nephthys through innocence, in the belief that she was Isis, sought to find this child; Dogs led Isis to it, it was brought up and became her guardian and attendant, receiving the name of Anubis, said to protect the gods just as dogs protect men.

Later Isis learned that the chest had been cast up by the sea near the land of Byblus in the midst of a clump of heather which in a short time ran up into a very beautiful and massive stock, which enfolded and embraced concealed the within its trunk. The king of the country admired the great size of the plant, cut off the portion that enfolded the chest and used it as a pillar to support the roof of his house.
Isis ascertained this by the divine intuation, and came to Byblus fragrant with ambrosia.  Isis was sent for the queen and became so intimate with the queen that the queen made her the nurse of her baby. They say that the king’s name was Malcander; the queen’s name some say was Astartê (Isis is the Egyptian name for Astarte, the major Phoenician goddess equivalent of the Sumerian goddess Ishtar) The Greeks would call Astartê later Athenaïs.

They relate that Isis nursed the child by giving it her finger to suck instead of her breast, and in the night she would burn away the mortal portions of its body. When the queen saw her child on fire, gave forth a loud cry and thus deprived it of immortality. Then the goddess disclosed herself tothe queen and asked for the pillar. She removed it with the greatest ease and cut away the wood of the heather wrapped it up in a linen cloth and had poured perfume upon it and entrusted it to the care of the kings; and even to this day the people of Byblus venerate this wood which is preserved in the shrine of Isis. Then the goddess placed the coffin on board a boat and put out from land.

In the first place where she found seclusion, when she was quite by herself, they relate that she opened the chest and laid her face upon the face within and caressed it and wept.

Isis proceeded to her son Horus (the Elder), who was being reared in Buto, and bestowed the chest in a place well out of the way; but Typhon, who was hunting by night in the light of the moon, happened upon it. Recognizing the body he divided it into fourteen parts and scattered them, each in a different place. Isis learned of this and sought for them again, sailing through the swamps in a boat of papyrus. The traditional result of Osiris’s dismemberment is that there are many so‑called tombs of Osiris in Egypt; for Isis held a funeral for each one of the 13 parts when she had found it. Of the parts of Osiris’s body the only one which Isis did not find was the male member, for the reason that this had been at once tossed into the river, and the lepidotus, the sea-bream, and the pike had fed upon it; and it is from these very fishes the Egyptians are most scrupulous in abstaining. But Isis made a replica of the member to take its place, and consecrated the phallus, in honor of which the Egyptians even at the present day celebrate a festival. Osiris consorted with Isis after his death, and she became the mother of Harpocrates (Horus the Younger), untimely born and weak in his lower limbs.

Later, as they relate, Osiris now god of the underworld came to Horus from the other world and exercised and trained him for the battle. After a time Osiris asked Horus what he held to be the most noble of all things. When Horus replied, “To avenge one’s father and mother for evil done to them,” Osiris then asked him what animal he considered the most useful for them who go forth to battle; and Horus said, “A horse,” because it served best for cutting off the flight of an enemy and annihilating him.

Now the battle, as they relate, lasted many days and Horus prevailed. Isis, however, to whom Typhon was delivered in chains, did not cause him to be put to death, but released him and let him go. Horus could not endure this and laid hands upon his mother and wrested the royal diadem from her head (some say cut off er head); but Hermes put upon her a head of a cow.

Horus was declared as legitimate child and Typhon was finally overcome in two more battles.

 

The transition can be wonderfully seen in the tomb of Senemut,  chief architect . astronomer, and former lover and favorite of lover of Pharaoh Hatsheput.

His tomb ceiling contains a presentation of the northern constellations with celestial objects, Osiris as Orion, Isis as Sirius, Horus as Jupiter, Horus again as Saturn.  A bird on the left represents Osiris as a phoenix linked with planet Venus as a morning star.  Another figure of Horus spears an ox representing Set-Apep as the constellation Ursa Major.

As we learned that the solar (astronomical) year was divided in twelve times thirty days and set in five to six days as a holiday. We understand the synchronization of the sun year and the moon loops in the symbolism as a whole.

The origins of the constellations in the Senenmut calendar are perhaps from about 2700 BC. It is depending on which star is the exact used in the constellation of either Ox or Scorpio.

The black headgears in the rows are originally dark red and are surely moons. The fifth from right have a star symbol in the name and a dog-head. Compared to the Sumerian Dog it maybe was to be synchronized with Sirius.

 The asterisks Scorpio and Ox are fix stars of equinoxes and then they originate from ca 3100 BC. We see also twelve wheels as a calendar contending months. The thirteen moons are below and the changing of years is in the middle. The ongoing year is a hippopotamus with a crocodile on its back and the new little crocodile in hand. We see Horus the time or sun using a Stele pointing at the Taurus and the opposite Scorpio with a moon symbol.

Some glyphs are special signs or icons in use with calendar or when writing about time. In the upper row fourth from right the symbol reads KA KA and in beginning of the third is a square with an eagle. In the second row the first wheel from right has a Hathor-cow icon with a year glyph.

In the suite behind Taweret is Isis the leading one as she has been in Egypt for thousands of years before this drawing.

 

Appendix:

Plutarch uses Greek names for most of the Egyptian gods and goddess  (capital letters) so here is a short overview

Sun (Helios)  AMUN-RA

Ra (Re) was thought of as the “Sun God”, and was once the most important God of the Ancient Egyptians.   Ra had been combined with Amon / Amun (the “hidden” aspect of the one God) as Amon-Ra/Re, and with Atum (the “potentiality” aspect of the one God) as Atum-Re/Ra. The Egyptians thought that Nut, the sky-goddess, swallowed Ra each evening, when he then travelled through the underworld only to reappear and be reborn again every morning. Personified in this way as the sun Ra represented life, rebirth, health and vitality. He is not to be confused with the henotheistic abstract God under Akhenaten, ATON or ATEN the new god of the sun, an incarnation of Re. It was a monotheistic attempt, a revolution lasting only on reign.

Rhea -NUT:    the sky-goddess, wife/lover/sister of Geb, the earth-god; represented as a woman, her naked body curved to form the arch of heaven. There is  a tradition that fromher five children, Osiris and Arueris were fathered from Helios, Isis from Hermes, and Typhon and Nephthys from Chronos.

Chronus – GEB: the earth-god; husband/brother of Nut;  member of the ennead of Heliopolis; represented as a man. Geb and Nut angered the sun god Ra, their grandfather, because they were locked in a perpetual embrace.  However, Nut was found to be pregnant and gave birth to Osiris, Horus the Elder, Set, Isis and Nephthys. According to the creation myth, Geb still longed for his sister. He wept when he was separated from her, and so created the oceans of the world.

Hermes – THOTH

Thoth (also Djehuty or Tehuty) is the archetypal Lord of Wisdom and of learning, writing, speaking, medicine, pictures and symbols. He protects all writers, teachers and scribes and was considered to be the tongue or heart of Ra. He is often shown with the head of the sacred Ibis bird, and sometimes is pictured as a baboon. Thoth is also a master magician and alchemist, and hence sometimes is shown with a lunar disc (symbolising magic) over his head.

MAAT

The Goddess Maat can be described as being the Animus of  Thoth – Thoth having a wife called Seshat. Maat personifies the concepts of truth, justice, balance, order and Ma’at (the Divine laws) which prevent a return to chaos. To the Egyptian people Maat ruled good behaviour, morality and spiritual ideals. Her symbol is the black and white ostrich feather, which symbolizes duality.

1) OSIRIS

Osiris was husband and brother of Isis, and brother to Nepthys, Set and Horus. He has been called later Lord of the Afterworld and Father of Kings. Because of his legend, which was to do with death and resurrection, he became associated with the cycle of life and death, and with the annual inundation of the Nile. He represents the wise spiritual father, encouraging us on the path of order and self-discipline.  Osiris was regarded as the son or earthly representative of Ra (God) just as Jesus was regarded  son of Godfather.

 2)  ISIS

Isis (Eset, Aset) is the wife of Osiris, mother of Horus the Younger and Bast and sister of Nepthys and Set. Her name means “seat” or throne, and this is often pictured symbolically as a crown upon her head. Isis stands for love, magic, medicine and fierce feminine energy. Sothis (Sirius) was identified with Isis in many Egyptian texts Plutarch states that “The soul of Isis” is called Dog by the Greeks. There is also no coincidence that Isis is the Egyptian name for Astarte the major Phoenician goddess, equivalent of the Sumerian goddess Ishtar related to Venus.

During the first century A.D., Alexandria, Egypt was a veritable hotbed of mystical activity, a crucible in which, according to Holy Blood, Holy Grail, “Judaic, Mithraic, Zoroastrian, Pythagorean, Hermetic, and neo-Platonic doctrines in an amalgamation or syncretism. Although they worshiped a Black Madonna as the Holy Virgin, she has an altogether different connotation to Gnostic than it does to Christians.  Legend connects this Black Madonna with both Isis and Magdalene.

3) Typhon   – SET

Set is the brother of Isis, Osiris, Horus the elder and Nepthys and wife of Nepthys and father of Anubis and uncle to Horus the younger. He is the equivalent of the archetypal “prince of darkness” in the Egyptian belief system, although he was intensly worshiped exactly for this.

4) Arueris – HORUS the Elder

Horus the Elder (Heru) was the son of Nut and Atum.

Harpocrates – Horus the Child (Hor or Har) was a sky and solar god, son of Osiris and Isis, presumable pre-natal.  He is known as the God of Joy and of Light, and his symbol is the hawk – master of the skies and protector of kings. Many people confuse him with his grandfather Horus the Elder.

5) Aphrodite    – NEPTHYS

Nepthys was the sister of Isis, Set, Osiris and mother to Anubis and wife to Set. Nepthys wears the horns and solar disc, or may be shown with the vulture headdress. She is the guardian of all things hidden or concealed or not yet come into form; of  dream and represents psychic receptivity. She is the other side of Isis – Isis representing light and generation, Nepthys representing dark and dissolution. Nepthys represents that which is invisible and the darkness, whilst Isis represents that which is visible and the light.

ANUBIS:

Son of Nepthys and Set (or possibly Osiris) and nephew to Isis. Anubis (also called Anpu, Inpu, or Imeut) is not to be mistaken with Wepwawet.  Anubis is the jackal (wolf or dog) – headed God of the Underworld and of Embalming. He is the protector of the dead and overseer of the mummification process. Anubis sits on the boundaries of the living and of the dead.

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Relevantes sites one really shouldn’t miss.

Cairo	Ancient Memphis Pyramids of Giza Pyramids of Sakkara Pyramids of Dahshour Pyramids of Abu sir Pyamids of Mydoum Pyramids of eleisht.html Pyramids of Hawara.html Pyamrids of Abu Rawash Pyramids of EL Lahaoun Pyramids of Hawara Pyramid of Mazghuna The Egyptian Museum The Coptic Museum The Castle of Saladin The Old Market “Khan El-Khalili” The Hanging Church Santa BarbaraOld Islamic Cairo: Sultan Hassan Mosque Refai Mosque
Luxor	Luxor Temple Karnak Temple The Colossi Of Memnon Valley Of The Kings Temple of queen Hatshepsut Temple Of Medinat Hapu of Ramses III Valley Of The Queens Valley Of The Nobles Temple Of Dendera temple of Esna Temple Of AbydosCourt of Ramses II, which includes a shrine to Thutmose III Mosque of Sufi Shaykh Yusuf Abu al-Hajjaj Chapel of Alexander the Great
Alexandria	The Castle of Qaitbay The Pompeii Pillar The Catacombs of Kom El-Shouqafa The Amphitheatre of Kom El-Dikka The Montazah Palace Gardens
Sinai	The city of Sharm El-sheik The city of Dahab The City of Nuweiba The City of Taba
Red Sea Coast	Monastery of St. Paul Mostry of St. Anthony Hurghada Safaga, Marsa Alam
Aswan	Temple at Philae, island ancients island surrounded with a dam and inside dry.  The main temple is dedicated to Isis and was the center of the cult of Isis and Hathor from 370 BC. The temple was finally closed by the Emperor Justinian in 535AD.
Centre of the Nile Valley (Minya, Asyut and Sohag)	Beni Hassan in Minya Monasteries of Asyut Temple of Abydos in Sohag Akhenaten’s city of Akhetaten at El- Amarna ( near Minya)