What happens to reports if we update our primary operating hours?

If your primary operating hours change by updating the Primary Business Hours, for example, going from 8 AM to 5 PM Monday to Friday to 6 AM to 6 AM Monday to Friday, data reflecting the new hours is only updated going forward and does not apply retroactively. Whatever business hours were in effect when a Contact was started will be used to determine business hours metrics for that Contact. If the primary business hours change after the Contact has already started, it will not impact that Contact, only Contacts that start after the primary business hours change will be impacted.