The office hours are a permanent service of the student body. During this time it is guaranteed that someone will be in office. You can find our current office hours in the sidebar.
During office hours somebody of the student body is there to answer your questions about your studies, to help you with a problem regarding a lecturer or to just to drink a cup of tea or coffee with. Oftentimes somebody will be in office outside of the official office hours also, so it can be worth to just come by. The office is also a community room where you can play games or talk, as long as you disturb no one working.