February 15th is Lupercalia

Lupercalia was a very ancient, possibly pre-Roman pastoral festival, observed on February 13 through 15, to avert evil spirits and purify the city, releasing health and fertility. Lupercalia subsumed Februa, an earlier-origin spring cleansing ritual held on the same date, which gives the month of February (Februarius) its name.

The name Lupercalia was believed in antiquity to evince some connection with the Ancient Greek festival of the Arcadian Lykaia (from Ancient Greek: λύκος — lukos, "wolf", Latin lupus) and the worship of Lycaean Pan, assumed to be a Greek equivalent to Faunus, as instituted by Evander.

In Roman mythology, Lupercus is a god sometimes identified with the Roman god Faunus, who is the Roman equivalent of the Greek god Pan. Lupercus is the god of shepherds. His festival, celebrated on the anniversary of the founding of his temple on February 15, was called the Lupercalia. His priests wore goatskins. The historian Justin mentions an image of "the Lycaean god, whom the Greeks call Pan and the Romans Lupercus," nude save for the girdle of goatskin, which stood in the Lupercal, the cave where Romulus and Remus were suckled by a she-wolf. There, on the Ides of February (in February the ides is the 13th), a goat and a dog were sacrificed, and salt mealcakes prepared by the Vestal Virgins were burnt.