FunCalendar is a prototype calendar application that tells you how much time you have for fun today. It was developed as an assignment for the Stanford online course on HCI, by Scott Klemmer. In addition to the source code, there's also live version.

This prototype has most core logic implemented, but there's no functionality to persist your events. The simple, but not so useful, solution, would be to save events to HTML5 local storage, like the application already does for settings. More useful, but trickier, would be to use events from your Google Calendar.

At present, I don't have plans for any substatial work on this.