Ancient Athenian
Sacred Days

Day 1
Noumenia | Nουμηνία

"They say Klearkhos (an Arkadian) discharges his religious duties and diligently sacrifices at the proper times, because each month on the Noumenia he places garlands on and cleans Hermes, Hekate, and the rest of the sacred things which his ancestors bequeathed to him, and also because he honors (them) with frankincense, and with barley cakes and with round cakes."

- Porphyry

Noumenia translates literally as "new-moon" but referred to the first visible sliver of the waxing crescent rather than the astrological New Moon we're familiar with today (recall a day began at sundown rather than sunrise) and Ancient Greece honored the Noumenia consistently across all the poleis (city-states). Plutarch called the Noumenia "the holiest of days", and in all of recorded history Athens never allowed any official or public meetings or festivals to infringe on it. It was a day of relaxing, feasting, banquets, and the pleasure and fraternity of the palaestra (gymnasium), while the Agora (marketplace) boomed with sales since all debts were collected the day before.

The Noumenia was celebrated with a public ritual on the Acropolis where the Epimenia sacrifice to the snake on Pallas Athena's shield took place, likely honored as a state protector. At home the statues would be garlanded and modest offerings of incense, particularly frankincense, and small cakes would have been made for the household gods. The theoi honored would have varied from polis to polis, but honors were likely given to many of the heroes and gods associated with the state, in addition to the household gods. Philocorus says this day is sacred to Helios and Apollon in particular. 

Klimpt's painting of Pallas Athena in her gold armor. She holds a spear in one hand and a Nike in the other, with her owl perched on her shoulder.

Some Household Gods

Hestia
Goddess of the hearth, home, and family, she is the spiritual epicenter of the religion and was represented by the physical hearth in the home. She is honored first and last in every meal, sacrifice, and ritual.

Zeus Ktseios
Zeus "of the Property", The Giver of Wealth. A snake-formed Zeus honored in the storeroom/pantry and represented by a jar with woolen fillets on the handles and a meal offering of panspermia (mixture of water, oil, and fruits and grains of all kinds) for the god. This was believed to protect the storeroom from thieves as well as foster continued blessings of 'wealth'. This jar is known as a kadiskos/kathikos and is emptied and refilled every Noumenia.

Zeus Herkeios
Zeus "of the Fence", defender against intruders. He is honored at an altar in the courtyard before the house. "Zeus Herkeios" was both a euphemism for family and the home (i.e. "Where is your Zeus Herkeios?")

Zeus Kataibates
Zeus "Who Descends", referring to his thunderbolts. It was common custom to have an altar to him in the house, courtyard, or next to the Zeus Herkeios altar and it was believed to protect the home from lightning strikes.

Zeus Meilichios
Zeus "the Propitious One", a chthonic snake-formed Zeus, though sometimes depicted as a man with a cornucopia. Aeschylus calls him the third protector of the house.

Apollon Agyeius
Apollon "of the Street", represented by a stone pillar on the street by the door of every house. The stone was decorated with fillets and oil poured over it, sometimes with an altar beside it. The stone was believed to protect the home from evil.

Herakles
Honored as an ancestral protector and general protector from evil. Sometimes his altar or image was placed on the street by the door next to or in place of the Apollon Agyeius, and homes traditionally had the inscription "Here the gloriously triumphant Herakles dwells; here let no evil enter" above the entrance to the home.

Day 2
Agathosdaimon | Aγαθὸσδαίμων 

Roman home fresco of a serpent

The second day of every month is sacred to the Agathosdaimon ("good-daimon"), a snake-formed house spirit thought to bring prosperity and blessings to the household. The spirit is sometimes likened with Zeus (house snakes were referred to as "sons of Zeus", or dios kouroi), or a companion to Agathe Tyche. At the end of the daily meal, a few drops of wine would be poured on the floor as a libation.

Day 3
Harpokration | Sacred to Athena & the Kharities 

Statue of Athena with her aegis depicted as an animal hide with the gorgon's snakes woven into the edges.

Sometimes called Athena's "birthday", but occurring every month. Artistophanes also claims this day as sacred to the Kharities (Graces). Athena was the patron of Athens and considered their divine protector and the Kharities had a thriving cultus there as well.

Some sources cite her sacred days as "all thirds", referring to the 13th and 27th/28th depending on if it is a Full or Hollow Month (recall the last decade of an Athenian Month counts backward). 

Statue of the three graces (charities / kharities) embracing.

Day 4
Sacred to Hermes, Aphrodite, Hermaphroditos & Herakles 

Statue of nude Hermes with his signature hat, traveler's cloak, and wand.
Statue of Hermaphroditos depicted similarly to Aphrodite and with a prominent penis.

There is an old proverb from Ancient Greece linking Herakles to the 4th, as well as a sacrifice in the Erkhia calendar by his devotees on the same day. Hermes is said to be born on the 4th in The Homeric Hymns, and Aphrodite in Hesiod's Theogony. Hermaphroditos also received offerings on this day due to their mythic ties between Hermes and Aphrodite.

Dramatic statue of Eros and Psyche in a lover's embrace staring into each other's eyes with wings unfurled.

Eros is linked through association with Aphrodite and according to Plato shares the day, but it is unclear whether that was at all reflective of current beliefs in Athens or other city-states for the time or not. Though we have one lone inscription dating a lost festival to him on the 4th, his associations for this day are otherwise scant

Statue of nude Aphrodite with her hair put up in curls and a shell at her feet.
Nude statue of Herakles at rest, leaning on prop with his lion's hide draped over.

Day 5
Inauspicious Day | Sacred to Horkos & the Erinyes 

"Be on your guard on all fifth days; they are harsh and dread.

They say that on the fifth the Furies [Erinyes] assisted

at the birth of Oath [Horkos], whom Strife [Eris] bore as a scourge to perjurers."

- Hesiod, Works and Days

Oil painting of the Furies screaming in Orestes' ear while he crouches in pain.

According to Hesiod "all fifth days" were sacred to Horkos and the Erinyes, thereby marking them as inauspicious days. However, it is unclear if this was observed in practice and most academics curiously omit mention of the 5th at all. It is possible it was an old belief that fell out of practice after Hesiod's time, or it may have been local to his region. However, there may be something to it in practice even if not officially recognized as inauspicious.

Putting aside the fact that Hesiod is the only extant source for this date, it is easily observed that the Athenian calendar doesn't place any festivals on the "all fifth days", except, that is, for festivals heavily related to The Mysteries or Death. The Genesia, the festival for the dead, takes place on the 5th, but if we look at the second 5ths (15th) we see The Greater Mysteries, Eleusinia, and Lenaia, and for the third 5th (25/26th) we see two apotropaic festivals, the Plynteria and the Lesser Mysteries. What all these festivals that fall on these "inauspicious" days have in common is an association with the khthonic, a term used generally to refer to all beings of the underworld whether god, daimon, or the dead. Coming in contact with khthonic forces, even through ritual, traditionally required purification afterwards. The Erinyes in particular were closely tied to death ritually and often receive sacrifices on days associated with the dead.

There is certainly a thematic trend between Hesiod's "inauspicious" days and khthonic ritual, but even knowing this it is hard to assert that the days were considered inauspicious in practice. Khthonic ritual and the Rites of the Dead are not theologically "inauspicious", but they are polluting. This again is not a bad thing, it is a natural thing, and not reason enough to avoid the pollution, but it does require cleansing rites afterward (which is typically a simple handwashing or bath).

Day 6
Sacred to Artemis 

Cartoonish original pottery image of Artemis with her hand on her hip, hair in a bun, and bow in her hand. Her decorative quiver across her shoulder. She is wearing long decorative dress.

Artemis was widely associated across Greece with the 6th and through the year a few of her Athenian festivals take place on the 6th day of the month such as the Kharisteria in Boedromion, the Elaphebolia in Elaphebolion, and the Delphinia in Mounichion. The Ancient Athenians believed her birthday was on 6 Thargelion, the first day of the Thargelia festival shared with her brother, Apollon.

Day 7
Sacred to Apollon 

Statue of Apollo with his hair in a curly bow akin to Aphrodite. His quiver and cloak wrapped across his back.

Complimentary to his sister, the 7th of every month was widely associated with Apollo across Greece, and no other god's festivals were ever held on it in Athens. Six out of the twelve months Apollo has official recognition on the 7th, including what the Athenians believed to be his birthday on 7 Thargelion, the second day of the Thargelia festival.

Day 8
Sacred to Poseidon & Theseus 

Pottery depiction of Poseidon, an old man with a long pointy beard, runs with a fish in one hand and his trident in the other.

Poseidon has ancient connections to Athens, as shown through his mythic contest with Athena for the city.

Theseus gains honors on this day as a son of Poseidon and was a widely beloved ancestral hero and founder of Athens and his corresponding festival, the Theseia, is on the 8th of Pyanopsion.  

Statue of Theseus, club in hand, slaying a centaur.

Day 16
Sacred to Hekate & Artemis 

Relief of triple-formed Hekate facing in three directions holding torches and jars.

Marking the middle of the lunar month Hekate would receive meal offerings at the crossroads just as she does on the last day of the month. It served as a home purification in the middle of the month as they were believed to carry the evil from the home in much the same way her ritual off-scourings were at the end of the month or during funeral rites.

Artemis is also associated with this day as it is "the second 6th" and it is believed she received her traditional "shining-all-round" cakes every month on this day, however, the scholia that makes the claim may have been discussing her festival in Mounichion where receiving such cakes was standard. 

Statue of Artemis in long billowing clothes and headdress. She has a soft expression as she allows a young deer to lick her fingers.

Last Day of the Month
Hene kai Nea | Triakas | Sacred to Hekate & the Dead 

Regardless of whether it was a Full or Hollow Month, the last day of the month fell during Hekate's Dark Moon when it was customary for a meal (deipnon) to be carried out to a crossroads and left as an offering for Hekate and/or the dead. The practice is similar in spirit to the offscourings deposited there for Hekate during house cleansings and implies offering the meal had the same purificatory effect on the household.

The last day of the month was also said to be the time in which Hekate escorted the recently dead to the underworld in her role as psychopomp, accompanied by a chorus of howling dogs. Athenian funeral custom dictates the last of post-funeral mourning rites be performed with a final meal for the dead left at a crossroads on the last day of the month. What's more, it was common enough in Ancient Greece for the hungry to snatch the meals before the spirits had a chance at them, leading many modern worshipers to interpret the offering as an act of charity for the less fortunate.

However, there is no indication that this was a monthly festival day. The practice was likely to have been a private one not recognized officially by the state (which would be typical of household cleansing rites) and likely wasn't a monthly obligation but would have been an option for anyone wishing to honor their dead or felt their home needed a cleansing or Hekate's protection. For modern purposes consider Hene kai Nea (Triakas in other city-states) as an optional day for household purification, protection, charity, and honoring the ancestors and recent-dead.

Statue of triple-bodied Hekate with studded spikes protruding from her head as a crown.

Notes

Bibliography