title: How to add minutes to the time part of datetime
body: <p>How to add <code>minutes(INT)</code> to the time part of <code>datetime</code> ?</p>
  
  <p>For example :</p>
  
  <p>If i have datetime variable like this :</p>
  
  <pre><code>  @shift_start_time =  2015-11-01 08:00:00.000
  
    @increase = 30
  </code></pre>
  
  <hr>
  
  <p>How to get the result :</p>
  
  <pre><code>2015-11-01 08:30:00.000
  </code></pre>