onTaskDragging event is fired while user is dragging a Task item.
One parameter is passed to the handler:
You may return false from this handler to stop dragging.
var dayX = new Date(2010, 5, 18); ganttChartControl.attachEvent("onTaskDragging", function(task,newdate){ if (newdate > dayX) { // Do not drag outside of date 5/18/2010 return false; } });