showing impact of delivery date of material

İ have a task that will start with its related material on site date. and this task is linked to its predecessor task with FS.but it shall be shifted till the related material delivered.i want to show the impact of the delay in material delivery date to the starting date of this task.
for example,
task A ..........
material on site date
.
Task B
........
impact
...........

i want to start this impact task with the finishing date af Task A and finish with the date of material on site date. and its duration must change automatically due to the starting date of task A and date of material on site..Briefly, is there a way of pointing out the duration of non working days between TASK A and Task B automatically?