title: Calculate "Busy hour"
body: <p>Baselines - table:</p>
  
  <p>date / time of call, duration of call</p>
  
  <p>How to calculate "Busy hour"? </p>
  
  <p><a href="http://en.wikipedia.org/wiki/Busy_hour" rel="noreferrer">http://en.wikipedia.org/wiki/Busy_hour</a> - In a communications system, the sliding 60-minute period during which occurs the maximum total traffic load in a given 24-hour period.</p>