title: How to get rid of 'minutes' in org-mode column view
body: <p>I am using Org-mode 8.0.2 and Emacs 24.1.1.</p>
  
  <p>How to change format of time displayed in column view from 'hh:mm' to simply 'hh'?
  So for 86 hours it would not be '86:00' but '86' instead.</p>
  
  <p>I can do that for tasks with subtasks by executing</p>
  
  <pre><code>(setq org-time-clocksum-format '(:hours "%d" :require-hours t))
  </code></pre>
  
  <p>But usual time-cells still use old format.</p>
  
  <p>My org-file:</p>
  
  <pre><code>* simple task 
  :PROPERTIES:
  :Effort:   9:00
  :END:
  * task with subtasks
  ** subtask 
  :PROPERTIES:
  :Effort:   9:00
  :END:
  </code></pre>
  
  <p>My column-view:</p>
  
  <pre><code>#+COLUMNS: %40ITEM(Task) %17Effort(Estimate){:}
  
  #+BEGIN: columnview :maxlevel 3
  | Task                 | Estimate |
  |----------------------+----------|
  | * simple task        |     9:00 |
  | * task with subtasks |        9 |
  | ** subtask           |     9:00 |
  #+END:
  </code></pre>
  
  <p>As a workaround, I can enter some dummy subtasks for each task without subtasks and move estimate there and then by limiting :maxlevel property I can hide those dummy subtasks. This workaround has some limitations and it is not an elegant solution whatsever.</p>