Nagios Report Help

Hello folks.

I am trying to find a report in Nagios on for the workhour period.

For exemple, I would like to know how the average of cpu and memory from a period 8:00 AM to 18:00 PM.

Actually, I am using the PNP Graphics, and I would like to know if its possible to get from the database only this periods.

If someone always did it, please help me.

Regards.