Workflow Rule for Tasks

Workflow Rule for Tasks

Within our tasks module we have three different categories for 'Status', one of which is 'deferred'.

I'm trying to create a workflow rule so that when the user selects 'deferred' it will automatically push the due date back by 5 days or so.

I've set it up so the execution of the workflow occurs when the user inputs 'deferred' into 'status' - I've put an instant action in as a field update - tasks >>>>> update >>>>> Due Date = execution + 5 days, however it isn't have the desired effect - any help?