adjective / noun
due
DOO/duː/
Required or expected as a matter of obligation.
The package is due for delivery by noon today.

Etymology
The central idea is something owed or required as an obligation. This broadened to something expected, while “in due time” expressed the set or appropriate time for it.
In context
What's normal at 10 weeks in pregnancy is not normal at 20 weeks, which is not normal at 30 weeks. So, establishing a due date is very important.
More examples
- An apology is due to everyone affected by the mistake.
- Please handle these records with due care.
- Members pay their dues at the beginning of each year.
- We give the volunteers their due for organizing the event.
Forms
due · dues
duly adverb — In the proper or required manner.
overdue adjective — Past the expected or required time.