Perfstack graph defaults itself to 7days in email report.

Hello,

I have created a perfstack graph about interface bandwidth and availability.
Also I could put it into a report and set it to be sent each day in email to various recipients.
My problem is that the report defaults itself to 7 days and that is how it is being sent in email, while I would like it to show the status of the last 24 hours.
Is there a way to force the report to be sent in email automatically showing the last 24 hours instead of the default 7 days?

Thank you in advance.