Time of Day filtering on Uptime Reports

We would like to have the ability to constrain the Uptime report to a customer's business hours. My customers don't care if the server was unavailable on a Saturday night for patching or other maintenance. What they care about is the uptime of their servers when they need them, during business hours. An example of the filter would be to calculate the uptime for a group of servers from 7AM to 6PM on weekdays. Alternatively, even if we could define the filters based on UTC time, we could do the conversion to match the customer's local business hours.