There is an option to sort the completed tasks by Completion date (see the screenshot below). However there are two issues with this:
- There is no option to sort by ascending or descending order
- The dates shown by the tasks are Due dates, not completion dates. Therefore from the project view it impossible to see how many tasks were completed in the specific day.
Exactly the same is related to the specific member view of the tasks (including My Tasks). So, it is much more intuitive and logical that the user sees completion dates when sorting by completion date is needed.