Assume you have a task that needs doing around every x days but it's not urgent and sometimes gets skipped.
When I do eventually complete that task late, have the option for that task to be X days after that day.
Currently it is X days no matter what.
Completing a long overdue task currently can be rescheduled X days later even if that day is in the past.
This results in needing to complete that task multiple times to get it back to the future.