Ask HN: Events Calendar similar to the amazing one at UC Berkeley?

The university-wide events calendar for UC Berkeley seems to me to be a marvel of engineering and is very well thought-through. Here is a description of the extensive planning done for the development of this software:

http://groups.ischool.berkeley.edu/EventCalendar/

and here is the events calendar itself:

http://events.berkeley.edu/index.php/calendar/sn/math.html

My university department is in dire need of a robust, well-thought-through, long-term, events calendar. Unfortunately this project is not open source and so we can't just grab it. Does anyone have any advice for a math department which wants high quality events calendar and basic, secure CMS without going corporate?