“Τρίτη Μεσοῦντος/ Τρισκαιδεκάτη/ Τρίτη ἐπὶ δέκα, XIII day.
From today’s sunset: thirteenth day of Pyanepsion.

Thesmophoria- KALLIGENEIA, ‘the fair birth’.
The day of rejoicing: plenty of festivity, sacrifices, feasts and dances.

Kalligeneia is a "δαίμων περὶ τὴν Δημήτραν”, nurse of Demeter and Kore, identified with Gaia and Demeter Herself. She is the Mother of the fair child, and the Mother Goddess par excellence…
“And You, august Goddesses, display a smiling and propitious countenance to our gaze; come into your sacred grove, the entry to which is forbidden to men; 'tis there in the midst
of the sacred orgies that we contemplate your divine features. Come, come now, appear, we pray it of You, oh, venerable Thesmophorae! If you have ever answered our appeal, oh! come into our midst.”
Aristoph. Thes. 1155

Let us now devote ourselves to the sports which the women are accustomed to celebrate here, when time has again brought round the mighty Mysteries of the great Goddesses… Spring forward with a light step, whirling in mazy circles; let your hands interlace, let the eager and rapid dancers sway to the music and glance on every side as they move.
CHORUS, singing
Let the chorus sing likewise and praise the Olympian Gods in their pious transport. It’s wrong to suppose that, because I am a woman and in this temple, I am going to speak ill of men; but since we want something fresh, we are going through the rhythmic steps of the round dance for the first time.
Start off while you sing to the God of the lyre and to the chaste Goddess armed with the bow. Hail Thou God who flingest thy darts so far, grant us the victory! The homage of our song is also due to Hera Teleia, who interests herself in every chorus and guards the approach to the nuptial couch. I also pray Hermes, the God of the shepherds, and Pan and the beloved Graces to bestow a benevolent smile upon our songs.
Let us lead off anew, let us double our zeal during our solemn days, and especially let us observe a close fast; let us form fresh measures that keep good time, and may our songs resound to the very heavens. Do Thou, oh divine Bacchus, who art crowned with ivy, direct our chorus; 'tis to Thee that both my hymns and my dances are dedicated; oh, Evius, oh, Bromius, oh, Thou son of Semele, oh, Bacchus, who delightest to mingle with the dear choruses of the Nymphs upon the mountains, and who repeatest, while dancing with them, the sacred hymn, Ευιε! Ευιε! Echo, the nymph of Cithaeron, returns Thy words, which resound beneath the dark vaults of the thick foliage and in the midst of the rocks of the forest; the ivy enlaces thy brow with its tendrils charged with flowers.
Aristoph. Thes. 947 ff.

(The “Mother of the fair child”, Paestum Museum)