SLA Working Hours
Working Hours define the calendar by which the SLA deadlines are calculated.
Use Working Hours to determine when time counts towards the SLA deadline and when it does not. Manage these in the Business Hours Manager (in the CSM AdministratorManagers menu).
Customer and Technician Working Hours
By default, the OOTB SLA configuration uses either a 24/7 calendar or the working hours of the technician (8-5 calendar on the same time as the CSM server). When the ticket is created, the customer's working hours are considered; however, they are not the frame of reference for the OOTB SLA deadlines. Consideration of the customer's working hours is limited to a match/no match determination, which helps CSM decide whether to start the clock (if the customer's hours match the technician's) or wait until the technician's working hours (if they do not match the customer's).
If you prefer, you can add the customer's working hours calendar and configure the SLAs to adhere to those instead.