title: PHP Calculating future date by adding days to a variable date
body: <p>I was looking at this post, and it is close to what I need: 
  <a href="https://stackoverflow.com/questions/1669165/php-how-to-count-60-days-from-the-add-date">PHP - How to count 60 days from the add date</a></p>
  
  <p>However, in that post, the calculation is performed by adding 60 days to the current date. What I need to do is calculate the date based on a variable date (<em>and not the current date</em>).</p>
  
  <p>Something like this:</p>
  
  <pre><code>$my_date = $some_row_from_a_database;
  $date_plus_10_days = ???;
  </code></pre>
  
  <p>Anyone know how to do that?</p>
  
  <p>Thanks</p>