Cross-Quarter Day is April 21, a day before Earth Day this year, the day on which the sun reaches halfway between equinox and solstice, and enters the late spring sign of Taurus. Now the meager inventories of change that characterized equinox quickly fill with new details each day. The floral and faunal fragments of the season multiply, literally filling in the space of Earth with tangible, visible clockwork. The first parsnips rise through the wetlands, and all major garden weeds are sprouting.