I'm trying to build a radar/spider chart with the following features:

(1) 24 hours (by 1-hour increments) indicated on the outer-most circle
(2) 7 days indicated on the nested circles
(3) occurrences indicated with a dot by date of occurrence (I want to be
able to plot by minute, even though the labels indicate whole hours only)

I'm having trouble plotting what should be a pretty simple chart. Any
ideas how I can set this up? What am I doing wrong?