fires when the user makes a single click on a cell on the x-axis (the Timeline view only)
| index | number | the column index of the clicked cell (zero-based numbering) |
| value | object | a Date object of the start time stamp of the clicked cell |
| e | Event | a native event object |
scheduler.attachEvent("onXScaleClick", function (index, value,e){
//any custom logic here
});