Ringing bells will greet CU-Boulder students at noon on Thursday, Sept. 5, to mark the anniversary of the University of Colorado's opening day 125 years ago. The carillon bells, located in Macky Auditorium, will ring 44 times in celebration of the first class of students. On Sept. 5, 1877 the doors of Old Main swung open to welcome CU's first class of 44 students and two instructors, including the president of the university.