3.14 are the first three digits of the number π, which is celebrated annually on 14 March across the world, including at the University of Silesia. The date is not accidental – it refers to the American date format for March 14th, i.e. 3.14. During the Pi Day, which begins each year with the inaugural lecture at 9.42 (3π), a festival of science and technology is organised. It is addressed to candidates for studies, as well as to students, teachers and graduates. The event programme consists of many popular science lectures, various workshops, shows and competitions with prizes, which will provide insight into the issues related to the number π, which is one of the most important mathematical constants.