JSON PHP Google Visualization

Trying to get my json output in the right format for a google visualisation line chart but I am clearly doing something wrong as it is returning table has no columns. As explained in the docs I am using Ajax to call a php page.

getData.php

<?php

    class MyDB extends SQLite3
       {
          function __construct()
          {
             $this->open('water.db');
          }
       }

    $db = new MyDB();
       if(!$db){
          echo $db->lastErrorMsg();
       } else {
          //echo "Opened database successfully
";
       }

       $sql =<<<EOF
          SELECT * from wT; 
    EOF;

      $data = array();

      $data['cols'][] = array('label' => 'Temperature', 'type' => 'number');
      $data['cols'][] = array('label' => 'Time', 'type' => 'string');

      $rows = array();
      $ret = $db->query($sql);


      while($row = $ret->fetchArray(SQLITE3_ASSOC) ){

        $temp = array();

        $temp[] = array('v' => (float) $row['fishTemp']);
        $temp[] = array('v' => (string) $row['time']);
        $rows = array('c' => $temp);


        $data['rows'][] = $rows;

      }

      $jsonTable = json_encode($data, true);

      var_dump($jsonTable);
      $db->close();

    ?>

base.html

<html>
  <head>
    <script type="text/javascript" src="https://www.google.com/jsapi"></script>
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
    <script type="text/javascript">
      google.load("visualization", "1", {packages:["corechart"]});
      google.setOnLoadCallback(drawChart);


      function drawChart() {
        var jsonData = $.ajax({
          url: "getData.php",
          dataType:"json",
          async: false
          }).responseText;

        // Create our data table out of JSON data loaded from server.
        console.log(jsonData);

        //var obj = window.JSON.stringify(jsonData);
        var data = new google.visualization.DataTable(jsonData);

        var options = {
          title: 'Title'
        };

        var chart = new google.visualization.LineChart(document.getElementById('chart_div'));
        chart.draw(data, options);
      }
    </script>
  </head>
  <body>
    <div id="chart_div" style="width: 900px; height: 500px;"></div>
  </body>
</html>

The output from the console looks like this....what am I missing?!

"{"cols":[{"label":"Temperature","type":"string"},{"label":"Time","type":"date"}],"rows":[{"c":[{"v":18.25},{"v":"2014-08-19 16:23:23"}]},{"c":[{"v":18.25},{"v":"2014-08-19 16:23:31"}]},{"c":[{"v":18.25},{"v":"2014-08-19 16:23:39"}]},{"c":[{"v":18.25},{"v":"2014-08-19 16:23:47"}]},{"c":[{"v":18.25},{"v":"2014-08-19 16:23:55"}]},{"c":[{"v":18.25},{"v":"2014-08-19 16:24:06"}]},{"c":[{"v":18.25},{"v":"2014-08-19 16:24:14"}]}

Loading dataTable with json accepts dates as a string in the following format: Date(year, month, day[,hour, minute, second[, millisecond]]) where everything after day is optional, and months are zero-based.

So for your first timeStamp, it should be :

{"v":"Date(2014,07,19,16,23,23)"}

If you want to use directly the milliseconds time:

{"v":"Date(1411154603000)}