Check Due Date Field

How do you check periodically (perhaps with cron jobs, rules, or in general) whether a CCK field which contains a date value (M-D-Y) has passed? Currently, I have created a content type with field that asks users to enter in a due date for when they want a project to be completed by. Several nodes are generated of this content type that contains this "due date" field.

I would like to check once a day whether the due date has been passed (check it against the current date) and send an e-mail to the set of users working on the project. I was hoping to use the rules scheduler but in many ways, it seems to be tied to triggered rules, meaning it can only be invoked when a certain event occurs, which doesnt happen for my set of users if they forget about a project.

Maybe someone can point me in the right direction.

I appreciate it.

Thanks