" Our language contained expressions that described the dusk—the dusk, that is to say, before sunrise—as “wolf-light”, lykophos or lykauges.{402} One story of Leto’s wanderings tells us that Zeus turned her for twelve days into a she-wolf. In this shape she came to the island of Delos from the Hyperboreans, the fortunate inhabitants of a northern country of the gods whither Apollon was thought to repair once a year. This is the reason, it is said, why she-wolves bear all their cubs within a space of twelve days in each year. The Delians actually stated{403} that she-wolves suffered travail for twelve days and twelve nights on end. "
― Karl Kerényi , The Gods of the Greeks