Final answer:
An exception is used in project management to denote special circumstances like holidays or events on a project calendar, differing from standard working times.
Step-by-step explanation:
A exception is added to the project calendar to denote something different from the standard working times. In project management, exceptions are used to adjust the project calendar for special circumstances that alter the regular schedule, such as holidays, company events, or other unique non-working days. These exceptions help the project team to accurately track the timeline and ensure that all planning reflects the actual working days available to complete the project tasks.