How do I know what the exact due date of my bill is?

The bills list will show you when your bill is due in terms of how long you have until the due date (for example, due in 3 days, due in 2 weeks, etc.)

However, once you go to the specific bill, you will be able to see the exact due date (for example November 30). 

You can also check the calendar for a list of your upcoming due dates.