title: A good Business calendar library in Java?
body: <p>Does anyone knows a good <strong>business calendar</strong> library in java? </p>
  
  <p>It should handle easy :) date calculations, taking holidays into account.</p>
  
  <p>Ideally, besides <strong>configuring holidays</strong> and company off days, we should also be able to <strong>configure 'working hours</strong>' on a day basis so we can calculate SLA's and KPI's on working hours.</p>
  
  <p>I know something like this is part of jboss jBpm, but I was wondering if their was any other project doing this.</p>
  
  <p>Off course, <strong>open source</strong> is a big plus point!  </p>