Here’s an interesting way to visualizing a timeline.  Categories of activity are shown around the wheel, while concentric rings visualize time of day.

For a media planning project, we needed to find a simple way to illustrate how people in a particular segment engage with different media. After some experimentation, we came up with this “media wheel” chart that summarizes 216 data points from a media spreadsheet. It shows (zoom in) where — at work, at home, in a restaurant, or in the car — people are when they read newspapers, watch TV, or listen to the radio throughout a typical day. Lighter hues correspond to higher levels of activity.

Personally, I would have flipped the axes (map time around the circle, like a clock, with concentric rings to indicate activities).  That would give an interesting biorhythm type of visualization, especially if “sleep” was one of the categories.

via Hill Holliday Blog » Visualizing Daily Activities With Media Wheel.