Assigning a calendar to a task or resource

To assign a calendar to a task, do any of the following:

Right-click the task, select Assign Calendar and choose a calendar from the list available.
Drag the calendar from Library Explorer and drop it on the task.
Select a calendar in the Calendar field in the Dates section of the Task tab of the Bar and Task Properties dialog.
Select a calendar in the Calendar field in the Dates section of the Task tab of the properties view.
Use the control in the Object Edit toolbar if it is available.

Assigning a different calendar to a task may alter its duration or start and finish dates for the following reasons:

The time units in the calendars may differ in absolute terms. For example, a working week may be 5d in one calendar and 6 in another, or a working day may be 7h in one calendar and 8 in another.
The calendars may have different holidays, overtime and other exceptions. For example, if a task that starts on 1st June will not be able to start on that date if you assign a calendar to it in which 1st June is a holiday.

When you assign a different calendar to a task, the Change Task Calendar dialog appears. You use this dialog to specify how the task's duration and start and finish dates are affected when the new calendar is applied.

To assign a calendar to a resource, use the Details tab of the appropriate Resource Properties dialog.