Create a sub task whose due date has a dependency on the
Parent's due Date (e.g. child/sub task's due date is 8 weeks
before parent's due date ?). For example, Parent Task Due Date is (say 30 November);
Child Task A due date is 2 weeks before
Child Task B due date is 4 weeks before
If Parent Task Due Date is changed, then Child Task Due Dates
are changed automatically. Additionally, a template could be created if there are many such Parent-Child dependent tasks.