Updating scheduled calls log

Updating scheduled calls log

I'm missing something or How can I update the call duration and status to "concluded" of a Schaduled Call??

After the call time schedule is overdue the call is hidded in callendar view and it is moved to closes activities on contact or lead view.

It is a bug or I'm missing something?? I want to be able to schedule and also update de call log informing duration and its conclusion. How can it be done?