Hi @Teri1, welcome to the Asana Community Forum!
When a task is reaching a due date, you will receive a notification to make sure it’s completed on time. You can enable email notifications or notifications for Tasks due today.
You can also have a look at this post with a workaround using Flowsana. cc @Phil_Seeman
Lastly, I recommend you to upvote for this feature in this thread Due Date Notifications for task that are overdue - #36 by Emily_Roman. We will make sure to update the main thread once we have any plans to implement this feature in Asana.
I hope this helps! 