Planner app for Teams data to PowerBI

Hi,

I recently started using the Planner app for teams. It still has limitations regarding some visual capabilities so naturally I wanted the data available in PowerBI. Connection to Dataverse behind the app worked fine for that purpose. The biggest issue I have for building a resource allocation timeline is that I'm unable to find daily or monthly level Assignments from the Dataverse. It's quite common for us that a person may work 50 hours on September on a task and only 20 hours on October for the same task. 

Is there a documentation available where I could find out how to get each data field visible in the app from Dataverse and specifically, are the daily/monthly level task assignments available in Dataverse? Planner App seems to break the assignments on daily level which would be gold for the PowerBI.

Thanks