title: Date format using gviz_api.py
body: <p>I'm using gviz_api (google-visualization-python)  to build some line charts. 
  <a href="http://code.google.com/p/google-visualization-python/" rel="noreferrer">http://code.google.com/p/google-visualization-python/</a></p>
  
  <p>I'e edited a line chart example taken from the google documentation.<br>
  However, I'm not sure how I would pass a date into the DataTable </p>
  
  <p>Here's the edited example I've been working with. 
  <a href="https://gist.github.com/3941946" rel="noreferrer">https://gist.github.com/3941946</a></p>
  
  <p>Here's the code I had a question about </p>
  
  <pre><code> # Creating the data
   description = {"year": ("string", "Year"),
               "sales": ("number", "Sales"),
               "expenses": ("number", "Expenses")}
  
   data = [{"year": '2004', "sales": 1000, "expenses": 300}, 
        {"year": '2005', "sales": 1200, "expenses": 400}, 
        {"year": '2006', "sales": 1300, "expenses": 500}, 
        {"year": '2007', "sales": 1400, "expenses": 600}, 
        {"year": '2008', "sales": 1500, "expenses": 800}]
    # Loading it into gviz_api.DataTable
    data_table = gviz_api.DataTable(description)
    data_table.LoadData(data)
  </code></pre>
  
  <p>How would I load a date into the DataTable using gviz_api?</p>
  
  <p>The google documentation describes how to creat a new Date() using javascript, however, I'd like to keep using gviz_api.py. </p>
  
  <p><strong>Notes from the google documentation</strong> 
  from <a href="https://developers.google.com/chart/interactive/docs/dev/implementing_data_source#jsondatatable" rel="noreferrer">https://developers.google.com/chart/interactive/docs/dev/implementing_data_source#jsondatatable</a></p>
  
  <p>*JSON Modifications
  Google's helper libraries, and all queries sent to Google, return a slightly non-standard version of JSON/JSONP. If you are not parsing the returned code yourself, this should not matter to you. The Visualization API client supports both standard and the modified versions of JSON. Here is a summary of the differences:</p>
  
  <p>JSON does not support JavaScript Date values (for example, "new Date(2008,1,28,0,31,26)"; the API implementation does. However, the API does now support a custom valid JSON representation of 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.</p>
  
  <p>JSON uses double-quotes for dictionary keys; the API implementation uses unquoted keys.</p>
  
  <p>JSON requires double-quotes around string values; the API implementation uses single     quotes.*</p>