Dartmouth is well known for its fierce school spirit and many traditions. The college functions on a quarter system, and one weekend each term is set aside as a traditional celebratory event, known on campus as "big weekends" or "party weekends". In the fall term, Homecoming (officially called Dartmouth Night) is marked by a bonfire on the Green constructed by the freshman class. Winter term is celebrated by Winter Carnival, a tradition started in 1911 by the Dartmouth Outing Club to promote winter sports. This tradition is the oldest in the United States, and subsequently went on to catch on at other New England colleges. In the spring, Green Key is a weekend mostly devoted to campus parties and celebration.