Web Filtering Acceptable Use Policy

I am looking to migrate from our current web filtering service to a Fortigate unit. The web filtering itself looks like it meets all the requirements, however there is one function I can't find. Every week (starting on Monday 00:00), the first time a user accesses the internet, they are required to accept the Acceptable Use Policy. This is just a straight-forward Accept button, no authentication required. It should reset every week. How can I implement this into the Fortigate web filtering?

Thanks