If to-dos without due dates were shown below the calendar, they would always be visible and we could drag-n-drop them onto the calendar. That would be awesome!
Just launched! — Enhanced Calendar
We just improved the calendar. You can now view unscheduled to-dos on the right of your calendar. Drag to-dos without due dates onto the calendar to set the due dates. Go to Releases > Calendar, click on Add calendar, and select a To-dos by due date calendar.
See how you can use the calendar to visualize your work.