From David Bourgeois via from at https://groups.google.com/d/msg/restya/xdbpj9crdFc/P8BInKgAFQAJ
Not being able to define a start date makes Gantt charts quite unusable. Without going too complicated, simply adding a 'Start Date' would at least show something more relevant as a project schedule overview.
Now my suggestion would be to add a field with the following options:
On 'Kanboard' and some other applications, dragging the task moves it on the gantt chart, adjusting the Start and Due dates automatically, while dragging the edges adjust the Start or Due dates only.
I think these only would make the Gantt chart much more useful.
Partly similar to previous issue: #701
I agree with