First day of each year where the temperature rises above 70F in regions of the US where temperatures in the winter months average at 30F and below. This day is characterized by excessive sunshine and general highs from a sense of spring in the air which prompts white people to wear revealing summer outfits that show off the pale, white skin they have been hiding all winter under peacoats and scarves.
"Man! Guys in tank tops on the quad? Girls with their short skirts exposing their painfully white legs? It's only March 21st! Is it White Slut Day already?"