Any user can create an unlimited number of calendars. From the main menu JIRA you should go to the "Calendar" and on the right side click "Add calendar" then chose "Create" link:
On the create\edit screen you can specify:
- calendar name
- output data (based on the project, favorites filters or JQL-query)
- working time
- background color of issues
- weekend showing
- need taskbar (only for server version)
- need to display the unscheduled tasks (only for server version)
- ability to display modes: Month, Week, Day, Timeline
- set the default display mode
- ability to show the avatar and username on issues panels calendar
You can create calendars for different cases: planning a specific project or product, employee, group of employees or the special issue types (such as a vacation or a business trip, or marketing activities):
- calendar for the project (only for server version)
calendar for groups (only for server version)
The calendar can be modified only by those who created it and who is included in the group jira-administrators. The administrator does not see calendars that are created by the user if the calendar was not shared.