Currently anyone that can view a space can perform actions on the calendar view of that space including:

• Adding a new calendar
• Importing an existing calendar

It seems problematic that if a user can only view content in a space, that they are able to modify the calendar view. On the other hand, there is no specific "add/edit calendar" permission in a space like there is for pages, blogs, comments and attachments. So it is unclear how this will work. One suggestion might be that only space administrators could add or import calendars but that is changing how team calendars works. Another might be that it should follow the "add/edit pages" permission.

In addition to that, users can currently create calendars and associate those calendars with spaces that they may only have view permissions on. Again, a suggestion might be to only allow this for space administrators as there is no "add/edit calendar" permission in a space. Or perhaps it should check against the "add/edit pages" permission instead.