Done: completed tasks
This list displays all completed tasks, sorted by performance date. When you change task status to Done or simply mark task as Done, it transfers to Done tab.
Completed tasks are as well shown in Calendar Tab with crossed out title.
The sync period of completed tasks is 1 month to today date.
Note: when you mark task as completed, it will disappear in Calendars app. This happens because standard calendar doesn't allow to complete tasks. So all Done tasks will not be shown in Calendars app.