Automatically delete completed tasks after a user-selected period of time
A setting which allows the user to have completed tasks automatically deleted X days after their completion date, X being a number chosen by the user.
Michael Finley commented
For daily recurrence tasks that have not been completed or just snoozed each day, please consider marking all tasks as completed or deleted except previous days task. Often the tasks don't remind after either missing a day or snoozing. Then the task gets stale and I have to mark each day complete until I get to the current date.