You can set the operational hours of your organization which calculates the due by time for a request. Besides setting specific working hours, you also have an option to set specific operational hours for any of the days of the week.
To set the organization's operational hours,
If you have already set the operational hours and now you wish to modify the same, you still need to follow the same procedure as specified above. But in this case, when you click Operational Hours from the Admin Home page, it will open the Operational Hours form with the details that have been set earlier. You can make the necessary modifications and then click on Save.