Virto Office 365 Calendar app has an ability to add external users to SharePoint calendar and an option to allows access for a certain calendar to all calendars and data sources created on current site collection.
For example, a company has several site collections for distinct departments. They don’t have access to each other calendars. You need also to create a calendar for HQ, this calendar must include all department calendars. In this case, you allow the HQ site collection calendar to have the access to all other site collection calendars. This can be made with a single click in calendar settings.
And the second new option is an ability to add external users to your Office 365 calendars. You have to share a SharePoint site collection with a user by entering his/her email and giving permission to current site. This external user must also have access to a list used in Virto Calendar you want to share. In other words, you set all the security permissions for this user in your SharePoint, not in Virto Office 365 calendar. If this external user has no access to a Exchange Calendar included as a data source to a Virto calendar with several data sources, he will not have access to this calendar at all.
Now, you can add this external user to a calendar subscription and set an edit permission level for him. You have to type the user’s email to add him to Virto Calendar.
You can learn more about all features of Virto SharePoint Calendar app on our site!