Tutorial Step 6: Set Schedule Exceptions
Still in calendar view, choose Extra & Off Hours from the toggle below the resource list, then choose a week in the calendar that appears. You can change the work hours for a specific week, to account for exceptions such as holidays or overtime.
Here Wednesday the 15th is an off-day. To quickly remove working time from the schedule, you can Shift-drag, creating a red box that marks normal working time as unavailable.
To add extra hours, double-click and drag to create a blue box which represents available hours apart from the normal working hours.
See synced changes to the calendar in Publishing and Subsciptions.