This demo shows how you can find out a screen coordinates of each data point, i.e. bullet.
To find X coordinate, we are using dateToCoordinate() method on the category axis. If we had a regular non-date-based category axis we would use categoryToCoordinate() instead.
For Y coordinate we utilize value axis' getCoordinate() method.
We catch a click on a bullet by setting up a listener to chart's clickGraphItem event:
"listeners": [{
"event": "clickGraphItem",
"method": function(e) {
// Find out X
var x = Math.round( e.graph.categoryAxis.dateToCoordinate(e.item.category) );
// Find out Y
var y = Math.round( e.graph.valueAxis.getCoordinate(e.item.values.value) );
console.log("x: " + x, "y: " + y);
}
}]