Calendar Events Library
The Calendar Events library handles calendar events. An event consists of and id, a start and end time, a description, what type of event it is, a URI, and inforamtion about how often the event occurs, when to remind, and so on.
The library also has some methods for tasks such as sorting the events, moving an event to the future, finding the next time that you've got five days for free, and getting all events by a certain type.