org-agenda-skip-scheduled-if-done

org-agenda-skip-scheduled-if-done is a variable defined in `org-agenda.el'.
Its value is

nil

Documentation:
Non-nil means don't show scheduled items in agenda when they are done.
This is relevant for the daily/weekly agenda, not for the TODO list. And
it applies only to the actual date of the scheduling. Warnings about
an item with a past scheduling dates are always turned off when the item
is DONE.

You can customize this variable.