PolarClock 3.0 is a hypnotic screen saver for Mac and Windows. It also can be used as a dashboard widget for OSX Tiger.
This screen saver is based on a color wheel of sorts, and developed in Flash. Polar Clock represents the passing of time on that wheel showing year, month, day hour minutes and seconds passing in time. the latest version has many configuration options also.
To understand how this works watch the video below.
You can check it out in action and download it for yourself at PixelBreaker