title: Convert Numbers into hh:mm time format
body: <p>I need to convert many values of this type:</p>
  
  <pre><code>855
  1148
  1030
  1132
  1136
  1142
  1217
  1216
  837
  1044
  </code></pre>
  
  <p>into time values like this:</p>
  
  <pre><code>08:55
  11:48
  10:30
  11:32
  11:36
  11:42
  12:17
  12:16
  08:37
  10:44
  </code></pre>
  
  <p>The end goal is to work out the average time from this list</p>