title: Convert duration in seconds to hours and minutes and skip empty values
body: <p>We have a Time Tracking model with a duration (in seconds) value that is always greater than 60 (1 minute).</p>
  <p>I need to convert the duration to hours and minutes if they are not zero and without zero at the start of hours or minutes.
  For example:</p>
  <pre class="lang-rb prettyprint-override"><code>duration1 = 63000  # expected value:  17 h 30 m
  duration2 = 28800  # expected value:  8 h
  duration3 = 1800   # expected value:  30 m
  duration4 = 300    # expected value:  5 m
  </code></pre>
  <p>I almost did, but have small problem with a zero values:</p>
  <pre class="lang-rb prettyprint-override"><code>Time.at(duration1).utc.strftime('%H h %M m').sub!(/^0/, '') 
  # 17 h 30 m
  
  Time.at(duration2).utc.strftime('%H h %M m').sub!(/^0/, '') 
  # 8 h 00 m
  
  Time.at(duration3).utc.strftime('%H h %M m').sub!(/^0/, '') 
  # 0 h 30 m
  
  Time.at(duration4).utc.strftime('%H h %M m').sub!(/^0/, '') 
  # 0 h 05 m
  </code></pre>
  <p>Thanks for answers.</p>