Nymphe

Nymphe (Greek: Νυμφη, meanging "bathe" or posssibly "Bridal") was the fourth eldest of the Horae. She was the daughter of Chronos and Ananke.

Myths & Legends
She represented the time of bathing. From the placement of her sisters, this time period is likely just before midday.

Accompany Helios
The Horae are known to accompany Helios (in some cases Apollo) into the sky, and take care of the horses that pull the chariot of the sun. As mentioned in the poem below, they would assist in taking the horses out to pasture, taking Helios' corona off his head, and putting away the chariot.

"'Far on the sloping margin of the western sea sinking Sol (the Sun) [Helios] had unyoked his flaming steeds, and laved their bright manes in the springs of Oceanus . . . and the swift-striding Horae (Hours), who strip him of his reins and the woven glory of his golden coronet, and relive his horse's dripping breasts of the hot harness; some turn the well-deserving steeds into the soft pasture, and lean the chariot backward, pole in air.'" "- Statius, Thebaid 3. 406 ff (trans. Mozley) (Roman epic C1st A.D.)"