Unfortunately the Product Schedule table is not available for Workflows and related field updates as of yet, so I don't think it would be possible to update the schedule using a workflow field update. You may want to explore a trigger to do so, if that can be done.
Unfortunately the Product Schedule table is not available for Workflows and related field updates as of yet, so I don't think it would be possible to update the schedule using a workflow field update. You may want to explore a trigger to do so, if that can be done.