The calendar linked above is a web interface to Kobus's public calendar and to the computer vision group calendars. The calendar is maintained by Kyle Simek.
Events beginning with asterisks (e.g., "*Office half hour") can be scheduled over the web. However, scheduling requests for office hours must be made by 6pm on the proceeding day.
If you are part of the computer vision group and need to know more about the group calendar or setting up your own calendar, see the Wiki page on the topic.