Taskworld calendar shows all your tasks in a calendar format. You can access it by clicking on Calendar tab in the Overview page.
Clicking a date allows you to create a task with that specific due date. You can also change the due date by simply dragging and dropping task to the desired date.
Changing the location for the task can also be done when creating the task by clicking on the Project Name>Tasklist Name on the upper right.
You can also sync your Taskworld calendar to Google Calendar, Outlook and OS X by clicking on Sync to Calendar.