We keep a web-based calendar using Google Calendar. There are several ways to access it listed below.
1) Click this button to add it to your Google Calendar. 
2) You can subscribe using any calendar application the supports the iCal standard using this URL: http://www.google.com/calendar/ical/bumc.durham%40gmail.com/public/basic.ics
Applications such as Apple iCalendar and Mozilla Sunbird.
3) You may also view the calendar in your web browser here.