THE HORAI (Horae) were the goddesses of the seasons and the natural portions of time. They presided over the revolutions of the heavenly constellations by which the year was measured, while their three sisters, the Moirae (Moirae) spinned out the web of fate. The Horai also guarded the gates of Olympos and rallied the stars and constellations of heaven. In Homer, who neither mentions their parents nor their number, they are the Olympian divinities of the weather and the ministers of Zeus; and in this capacity they guard the doors of Olympus, and promote the fertility of the earth, by the various kinds of weather they send down.
Hesiod, Theogony 901 ff (trans. Evelyn-White) (Greek epic C8th or 7th B.C.) : "Next he [Zeus] led away bright Themis (Divine Law) who bare the Horai (Horae, Seasons), and Eunomia (Good Order), Dike (Justice), and blooming (thallô) Eirene (Irene, Peace), who mind the works of mortal men, and the Moirai (Moirae, Fates) to whom wise Zeus gave the greatest honour, Klotho (Clotho), and Lakhesis, and Atropos who give mortal men evil and good to have." [N.B. Eirene might also denote spring, and Eunomia good pastures.]
Part of a much bigger project that will be uploaded in a few days, called "Promethean Fire".