Charts Line Chart Date doesn't change

[GoogleCodeExporter]

What steps will reproduce the problem?
1. https://code.google.com/apis/ajax/playground/?type=visualization#line_chart
2. Changed all the first column items to Date(epoch_secs) format
3. Clicked Run Code
4. Mouse over date labels at bottom - they are all the same

Here's the whole code I used:

function drawVisualization() {
  // Create and populate the data table.
  var data = google.visualization.arrayToDataTable([
    ['x', 'Cats', 'Blanket 1', 'Blanket 2'],
    [Date(1399433000),   1,       1,           0.5],
    [Date(1399433100),   2,       0.5,         1],
    [Date(1399433200),   4,       1,           0.5],
    [Date(1399433300),   8,       0.5,         1],
    [Date(1399433400),   7,       1,           0.5],
    [Date(1399433500),   7,       0.5,         1],
    [Date(1399433600),   8,       1,           0.5],
    [Date(1399433700),   4,       0.5,         1],
    [Date(1399433800),   2,       1,           0.5],
    [Date(1399433900),   3.5,     0.5,         1],
    [Date(1399434000),   3,       1,           0.5],
    [Date(1399434100),   3.5,     0.5,         1],
    [Date(1399434200),   1,       1,           0.5],
    [Date(1399434300),   1,       0.5,         1]
  ]);

  // Create and draw the visualization.
  new google.visualization.LineChart(document.getElementById('visualization')).
      draw(data, {curveType: "function",
                  width: 500, height: 400,
                  vAxis: {maxValue: 10}}
          );
}
​

Original issue reported on code.google.com by goodna...@gmail.com on 7 May 2014 at 3:03