Proper contest ended early (3)

I believe the answer is:

due

I'm a little stuck... Click here to teach me more about this clue!

'proper' is the definition.
(I've seen this before)

I can't explain the rest of the clue.

(Other definitions for due that I've seen before include "Deserved or unpaid" , "Expected; appropriate" , "Owed, or payable immediately" , "Expected; proper" , "Expected, scheduled" .)

I've seen this clue in The Sun.

Want a hint initially instead of a full solution? Install my app