[web2py] date variables, json and jqplot

[Rick]

Hi,
I want to draw a graph with jqplot, where the x-axis is a date-
timeline, but I get this message:
TypeError: datetime.date(2011, 10, 2) is not JSON serializable
Does anyone know an easy way to pass date variable to json?

Thanks in advance for help. Here is some code from the files:

************

>From the controller file:
points=[[point.thedate, point.value] for point in pointlist]
return dict(points=points)

************

from the view file:
<script>
<!--
jQuery(document).ready(function() {
  $.jqplot('chart1',  [{{=simplejson.dumps(points)}}], {
     title:'Default Date Axis',
    axes:{xaxis:{renderer:$.jqplot.DateAxisRenderer}},
    series:[{lineWidth:4, markerOptions:{style:'square'}}]
  });
});
-->
</script>
<div id="chart1" style="margin-top:20px;margin-left:20px; width:200px;
height:200px;">
</div>