A term coined by Bill Simmons of ESPN in reference to the day when the weather finally becomes warm enough in a notoriously cold part of the country (i.e. the Northeast) that convertible tops can go down and girls can wear miniskirts and halter tops outdoors. Usually occurs in April.
The first really nice day of spring in the Northeast. Women who have been wearing heavy clothes all winter long, suddenly in unison break out short skirts and tank tops.