How to Edit a Calendar Item
You edit a calendar item in System Center 2012 – Service Manager to update work days, work hours, and holidays. After you edit a calendar item, you will use it as part of a service level objective, where it is measured against a time metric. If the calendar is already associated with a service level objective, it appears in the Related SLA(s) area.
When you update an existing calendar item, the update is effective for incidents and service requests created afterward; however, the updates do not affect existing incidents.
To edit a calendar item
In the Service Manager console, click Administration.
In the Administration pane, expand Service Level Management, and then click Calendar.
In the Calendar list, select an existing calendar, and then in the Tasks pane, under <CalendarName>, click Properties.
In the Create/Edit Calendar dialog box, modify any of the following items, as needed:
Working days and hours
Click OK to close the Create/Edit Calendar dialog box.