Celebrating the 100th Hey Day on April 30, 2015, members of Penn’s Class of 2016 marched with canes along Locust Walk, wearing red shirts and flat-brimmed, faux-straw hats.

Hey Day, a tradition that is unique to Penn, marks the moment when juniors “move up” to seniors, following the last day of classes.

Each year, the event begins with a class picnic and continues with a procession through campus, which stops at the steps of College Hall. There, Penn President Amy Gutmann greets the students and delivers a three-question test. On the 100th occasion, Gutmann asked:

• Who was the founder of the University of Pennsylvania?
• How many Hey Days have there been?
• True or False: The Class of 2016 will be the best class ever.

After shouting their answers, Gutmann said the words that every junior longed to hear: “By the powers vested in me by the Trustees of the University of Pennsylvania, I hereby pronounce you, seniors!”

The senior and junior class presidents followed with brief speeches and, in keeping with tradition, took bites out of each other’s hats. The crowd of newly appointed seniors cheered and sang “The Red and Blue.”

Hey Day has evolved from a formal occasion where participants donned robes and gowns to a more exuberant outdoor affair—though it is an event that still tips the hat to previous generations of Penn students.

There are two feasible explanations as to why the name of “Hey Day” was chosen, according to the University Archives and Records Center.

An article in a 1916 edition of The Pennsylvanian suggests a committee assigned to think up a proper title for the newly established Moving-Up Day selected “Hey Day,” as it was a day of rejoicing.

Another possibility is that the phrase referenced “the heyday of someone’s career.” The Class of 1916’s Eugene H. Southall, who served as The Pennsylvanian’s editor-in-chief, jokingly suggested that “Straw Hat Day be known henceforth as Heyday and that the then scattered events of importance be concentrated in one day, which would represent a sort of … heyday of college life and activities.”