Caliander is the calendar that lets you create events faster and with less effort, keeping you on top of things with its smart and unique presentation. It uses the same calendar database as Calendar.app, so it syncs with all your devices as usual, and all your events are there-no migration needed!
Caliander is all about removing the effort it takes to maintain a calendar.
A warning about CalDAV, Entourage and subscribed-to calendars: While Caliander shows and edits your CalDAV calendars, it can't sync these calendars on its own because of technical reasons; you have to start iCal to perform a sync. Similarly, you have to start iCal to refresh your subscribed to Calendars. There is no support for Entourage calendars, unfortunately.
Note: The demo version is currently at 1.2.1. The version available for purchase on the Mac App Store is 1.2.2.