Ever Set a Task in MS Project but Forgot Which Calendar the Task is Using?
Try the checklist below when it is difficult to understand which calendar is being used for calculating a task Finish date:
v Check the Project Calendar in the Project, Project Information… form,
v Then check the Task Calendar in the Task form Advanced tab or a Task Calendar column,
v Next check if resources are assigned to the task,
v Finally check the Resource Calendar for holidays.
The rules are as follows:
v When NO Task Calendar and NO resources are assigned, then the Project Calendar is used.
v When a Task Calendar is assigned and there are NO resources assigned then the Task Calendar is being used.
v When Resources are assigned and NO Task Calendar then the Resource Calendar is used.
v When Resources and a Task Calendar are assigned, then the commonly available time from both calendars is used to schedule the task.
v When Resources and a Task Calendar are assigned and the Scheduling ignores resource calendars is checked, the Task Calendar is used.
Note: A common mistake is assigning a task an edited task calendar, then at a later date assigning resources without editing the resource calendars to match the task calendars and not realizing that the task durations no longer calculate the same.