NVD3 tooltip change event

Question

I have a nvd3 chart and a html table. I need to update table values as the user moves the mouse over the chart. Is there an event I can use to catch a nvd3 tooltip change and get the date value at the current mouse position?

My first idea was to get the nv.tooltip values on mousemove over the chart element. Not of much help.

$('#chart').mousemove(function(e) {
    console.log(nv.tooltip);
});