Snakes' day. Awakening of the Nature after the winter.
Celebrating the battle of the right God against the Chaos symbolized by the Snake. You do remember all of that: Marduk against Tiamat, Perseus against Medusa, Saint George against the Dragon...
In those battles the Chaos side was represented mostly with female characters, but the God's victory is not definitive forever, only for the period.
All the more, the coming spring will unevitably bring some chaos to the hearts. We should just know the limits.