Repeating tasks option

When a task repeats there should be an option to specify whether the next occurence is scheduled from the date the task was due OR the date the task was actually completed. Eg if a task is scheduled to repeat monthly; the due date is 1st of Mar; but the task is only marked completed on 10th Mar, this controls whether the next instance is scheduled for 1 Apr or 10 Apr. Something like a credit card bill you would want the former; but something like washing the car you would want the latter.