In colder climates, That Day is the first day where the girls break out the short-shorts and tank tops and show that skin that has been in hiding all winter.

That Day is a very celebrated day on college campuses.

On That Day eye candy abounds.

The exact date of That Day varies from year to year and from place to place. It usually falls in the months of March or April.

The first day of every spring when the winter weather parts and the first hint of warmth brings people outdoors in droves. The people, whom you've curiously never seen before had effectively been in hibernation and their emergence triples the population of your town, city, college, etc. Sun on That-Day is key. Activities often include frisbee, hacky-sac and basking in the sun. The effects of That-Day are most evident on college campuses.