Best I’ve found
I used Now Up-to-Date for years—long after it died, in fact. This program, by some of the original developers of NUD, is a worthy, and in some ways superior, replacement. It does essentially everything I need it to. There are a few places where I wish the functionality were greater, or the interface were slicker, but there’s nothing really wrong with it. A great replacement for Apple’s Calendar and Reminder programs.
Calion about BusyCal 2