When a user changes or moves a task in the Gantt area all its successors (and the successors successors) must move with the same time value. How do I do this in VB6?
In the phGantTimePackage you need to move all the successors yourself. There is no built in function that does this.
One solution is to build a function that moves all time items on a GanttRow a certain amount of time and also calls itself recursivly for all its child nodes. And call this method in the IphGantX3.OnValueChangedGantTime event.
For a sample of doing complete iteration of the object model of the phGantt please see this article: Iteration