Open source calendar UI

I recently created a calendar for ecological events for my wife.

The center piece of it is, of course, the calendar widget. At first I intended to use drupal's calendar module. However, once I tried it, I was let down. Drupal's calendar, even though it looks "good enough" is no piece of eye candy. It lacks a nice way of displaying multi-day events and, what is even worse, it cannot display overlapping or simultaneous events as nicely as google calendar does.

That's why after some consideration I decided to use google calendar for displaying events. Yes, I lose the ability to control all the information from one central place (and there were some features that could have used this nicely, such as the ability for visitors to suggest upcoming events that are not in the list), but in the end making the calendar nice and easy to use is priority.

Does anyone know any goog open source calendar UI examples?