Explorer option not working if X axis is Date (Chart API)

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Copy and paste the code below in playground and try to zoom in

function drawVisualization() {
    // Create and populate the data table.
    var JSONObject = {
      cols: [{id: '', label: 'X', type: 'date'},
             {id: '', label: 'Y', type: 'number'}],
      rows: [{c:[{v: new Date(2008, 1, 1)}, {v: 30000}]},
             {c:[{v: new Date(2008, 1, 2)}, {v: 14045}]},
             {c:[{v: new Date(2008, 1, 3)}, {v: 55022}]},
             {c:[{v: new Date(2008, 1, 4)}, {v: 75284}]},
             {c:[{v: new Date(2008, 1, 5)}, {v: 41476}]},
             {c:[{v: new Date(2008, 1, 6)}, {v: 1476}]},
             {c:[{v: new Date(2008, 1, 7)}, {v: 4176}]},
             {c:[{v: new Date(2008, 1, 8)}, {v: 416}]},
             {c:[{v: new Date(2008, 1, 9)}, {v: 3476}]},
             {c:[{v: new Date(2008, 1, 10)}, {v: 41176}]},
             {c:[{v: new Date(2008, 1, 11)}, {v: 41476}]},
             {c:[{v: new Date(2008, 1, 12)}, {v: 4376}]},
             {c:[{v: new Date(2008, 1, 13)}, {v: 41476}]},
             {c:[{v: new Date(2008, 1, 14)}, {v: 46476}]},
             {c:[{v: new Date(2008, 1, 15)}, {v: 7476}]},
             {c:[{v: new Date(2008, 1, 16)}, {v: 3322}]}]};

    var data = new google.visualization.DataTable(JSONObject, 0.5);

    var chart = new google.visualization.LineChart(document.getElementById("visualization"));
    chart.draw(data, {
        height: 400,
        width: 800,
       explorer: {actions: ["dragToZoom", "rightClickToReset"]}
    });
}
google.load("visualization", "1.1", {packages:["corechart"], callback: 
drawVisualization});

What is the expected output? What do you see instead?
Explorer option should work.  It works if X axis contains "number" data.

What version of the product are you using? On what operating system?
Tested on Win 7 IE, FF and Chrome.

Original issue reported on code.google.com by mark.d.c...@gmail.com on 3 Dec 2013 at 2:44