Second Saturday in April
On the second Saturday of each month members of Hellenion pour a libation to one of the Olympians on the same day, from wherever they may be, with whomever may join them, around the world. In this way, whatever else we do to celebrate Hellenic occasions, we are united in doing the same action on the same day. In April, we honor Artemis.
Daughter of Zeus and Leto and sister to Apollo, Artemis (Ἄρτεμις) is the goddess of wild animals (as Potnia therōn) and yet of hunting and the bloody aspect of war. Yet she is also the protector of young creatures of all kinds, including newborns and women giving labor, and the initiation of young maidens. She is shown in the Iliad as an awkward adolescent and is pictured in art as a boyish girl wearing a short tunic, bearing bow and arrows and accompanied by a stag or doe. Like her brother, she is associated with dancing and music, but is also associated with bloody sacrifices, cruelty, savage cries and darkened groves. As the pure maiden, she expects hunters and likely soldiers to be pure, too, and she receives her share in deaths (from Burkert, Greek Religion, p. 149-152).
She receives her honor in April because of the proximity of the festival of Mounykhia and because of Earth Day. Pour a libation to Her, read the one of the Hymns to her: Homeric Hymns to Artemis (Hymn 9 and 17), and the Orphic Hymn to Artemis (Hymn 36).
Further Reading & Sources
Beautiful passage on Artemis by W. Otto
Burkert, Walter, Greek Religion, English version 1985