This is actually pretty cool (check out the YouTube video). I wish it was easier to add events.

The use case cited is bus schedules, but it is really quite broadly applicable. Any time you have something "coming up" you can see at a glance how much time you have left till then.

I think many more people would use this if it was turned into a product, rather than an SDK or a collection of .jars.

EDIT: Found it! Check out HeliCal: http://www.lri.fr/~dragice/helical/