How does Red Hat define standard business hours?

How does Red Hat define standard business hours?
Red Hat follows the generally accepted practice that Standard Business Hours are either 9:00 AM to 6:00 PM (0900-1800) local time for North America or 9:00 AM to 5:00 PM (0900-1700) for outside of North America. Standard Business Hours do not include weekends or local public holidays.

Calculation of Standard Business Hours is done by the location set in the customer’s Red Hat Customer Portal (sometimes called the RHN ID). For example, if a customer is in New York and has their Customer Portal account set with their correct address information, then Standard Business Hours will be 9am-6pm EST or EDT, depending on the time of year.

How does this work in practice?

If a North American customer were to contact a Red Hat regional support office at 5:45pm (17:45) local time with a critical system failure and the customer has Standard support then the initial response SLA for a Severity 1 critical issue is 1 business hour. Because the end of the local business day is 6:00pm (18:00), the customer may not receive a response until the following business day. If this event occurred on a Friday and Monday is a local holiday then the case would not be worked again until normal business hours resume.