This one is really easy

Each to do can have a due date assigned, which affects three things:
- Folder in which the to do will be moved
- It’s gonna be added to the iCal export
- Affects your productivity score
There are 3 possible categories you to do can fall in after setting the due date.
- Today
- Next 7 days
- Overdue
Every to do with due date is also added to the iCal feed, which you can import to your calendar.
