 <p>You can convert with <code>strtotime()</code> to safely date-manipulating and then you can reorder the array:</p> <pre><code>$dates = array( '2015-02-13', '2015-04-21', '2015-08-18', '2015-11-26', '2015-09-15', '2015-01-07', '2015-02-11', '2015-07-14', '2015-03-02', ); $newArray = array(); foreach($dates as $value) { $newArray[] = strtotime($value); } sort($newArray); var_dump($newArray); </code></pre>