When you need a Task to occur before or after the milestone date of an Event associated with a Person, Transaction or Project, you will want to select the option to make the task contingent.
To create a new Task, select the plus sign next to Tasks in the Left Navigation Bar.
In the New Task form fill out the Task Details, Who Task is Assigned to, who the Task is for, and the Task Visibility. You will also need to select a Due Date before you finish and click Create Task.
To make this task Contingent, select Make Contingent. Fill in the # of days, select Before/After, & the type of Event. Finish by clicking Create Task. Now your task will be Contingent!