Set item.Start at current mouse position on drop item over timeline

[neoburgos]

Hello.
(sorry if I explain myself wrong)

I´m using this example:
https://visjs.github.io/vis-timeline/examples/timeline/other/drag_drop.html

In this code:
https://pastebin.com/Pg0JRsfG

I want drop an item with:
start time : same I get when I do:

timeline.on('drop', function (properties) {
console.log('time at this point: '+properties.time);
});

end time : start time + something (no problem here)

function handleDragStart(event) {
var dragSrcEl = event.target;
event.dataTransfer.effectAllowed = 'move';
var item = {
id: new Date(),
type: 'range',
content: event.target.innerHTML.trim()
};
item.start = WHAT CAN I USE HERE?
item.end = new Date(10006060 + (new Date()).valueOf());
event.dataTransfer.setData("text", JSON.stringify(item));
}