Log Daily Detailed Usage for Users ?

Hi, we are currently using a bandwidth manager and its core developers said, we cannot have DAILY DETAILED USAGE for the customers, as it works in session based calculation.
Means, till the customer has logged out, the current session is active and it will only count, once the session ends.

While all of our customers ask for daily detailed data usage.
They dont care session based or they are not able to accept this limitation.

So, cant we have detailed data usage, no matter anyone is logged in or out ??

Im asking this, because I have seen it working in some other bandwidth manager, and they also use Microtik.

Let me know, how to achieve this ?

All I need to show my customers is their daily data usage.

Use the Acct-Interim-Interval RADIUS attribute to force a status update every so often to the RADIUS server.
http://wiki.mikrotik.com/wiki/Manual:RADIUS_Client#Access-Accept

How does that solve the purpose ?

Part of the interim update contains the bytes sent and received for a given user.