title: Convert HH:MM:SS to hours (for more than 24 hours) in R
body: <p>I would like to convert hours more than 24 hours in R.</p>
  
  <p>For example, I have a dataframe which contains hours and minutes like [HH:MM]:</p>
  
  <blockquote>
    <p>[1] "111:15" "221:15" "111:15" "221:15" "42:05" </p>
  </blockquote>
  
  <p>I want them to be converted in hours like this:</p>
  
  <blockquote>
    <p>"111.25" "221.25" "111.25" "221.25" "42.08333333"</p>
  </blockquote>
  
  <pre><code>as.POSIXct() 
  </code></pre>
  
  <p>function works for general purpose, but not for more than 24 hours.</p>