Create a task that can be planned in repeated separate instances without clearing

The ability to create a task that isn't done 'every x days' but done 'x days per y' (for instance, working out 3 days a week) where planning that task keeps that main task in the inbox, allows to be relocated to another day's plan when missed, and makes a reminder similar to an overdue reminder if there are only so many remaining days in a week to accomplish the remaining uses of that task.