Quad Day

From U of I Wiki

Quad Day is a rollicking feast of an event, a moment when the Quad becomes a sea of Involved Undergraduate Bodies engaged in festive ebullience! This is because Quad Day is the day, early each fall semester, when the quad is jam-packed with student groups. On quad day, you will find thousands of other strolling revelers checking out the range of student groups at the U of I -- everything from the Underwater Hockey team to the Herb Society.