title: How to subtract two dates in Laravel5.4
body: <p>I'm projects table that users projects is saved in it and have start_time and finish_time and price,I give it as form that has this code:</p>
  
  <pre><code>&lt;div class="form-group"&gt;
     &lt;input type="date" class="form-control" name="start_time" &gt;
   &lt;/div&gt;
  
   &lt;div class="form-group"&gt;
   &lt;input type="date" class="form-control" name="finish_time" &gt;
   &lt;/div&gt;
  
   &lt;div class="form-group"&gt;
   &lt;input type="text" class="form-control" name="price" &gt;
   &lt;/div&gt;
  </code></pre>
  
  <p>Now,I Want subtract dates and if result be Negative Can multiply price and result,How I can do this?</p>