title: add +1 hour to datetime.time() django on forloop
body: <p>I have code like this, I want to check in the time range that has overtime and sum it.</p>
  
  <p>currently, am trying <code>out.hour+1</code> with this code, but didn't work.</p>
  
  <pre>
  
      overtime_all = 5
      overtime_total_hours = 0
      out = datetime.time(14, 30)
  
      while overtime_all > 0:
          overtime200 = object.filter(time__range=(out, out.hour+1)).count()
          overtime_total_hours = overtime_total_hours + overtime200
          overtime_all -=1
  
      print overtime_total_hours
  
  </pre>
  
  <p>how to add <code>1</code> hour every loop?...</p>