It would be extremely useful to have the ability to drag a task from the
daily or weekly calendar view tasklist and drop them onto the calendar to
make an appointment / event.

In this way, the user create tasks and allocate blocks of time to complete
each task. 

Accordingly, if it would be great to have a "create appointment / event"
option when the right mouse button is used on the tasklist. 

This would provide far better integration between the tasks and the
calendar - the user can plan their tasks, and then allocate time for
completion by creating appointments. 

It will also provide a historical record of when tasks were worked on which
may be important to some users. 

I have no idea if this functionality has been suggested previously. My
apology if this is the case.