I want to dynamically udpate canvasOverlay property of jQuery jqPlot. This will provide the effect of a timeline in my jqPlot. This effect should be similar to the one shown in this jFiddle. However, instead of drawing points, I want to update canvasOverlay property every second:

                canvasOverlay: {
                    show: true,
                    objects: [
                        { rectangle: { xmax: new Date(), xminOffset: "0px", xmaxOffset: "0px", yminOffset: "0px", ymaxOffset: "0px",
                                            color: "rgba(0, 0, 0, 0.1)", showTooltip: true } },
                    ]
                } 

How can I do this? What are the functions I should use?

UPDATE:

My idea is to do something like this:

                    canvasOverlay: {
                        name: 'current',
                        show: true,
                        objects: [
                            { rectangle: { xmax: new Date(), xminOffset: "0px", xmaxOffset: "0px", yminOffset: "0px", ymaxOffset: "0px",
                                                color: "rgba(0, 0, 0, 0.1)", showTooltip: true } },
                        ]
                    } 

/...

var co = plot.plugins.canvasOverlay;
var current = co.get('current');

current.options.objects.rectangle.xmax = new Date();
co.draw(plot);