365 Shared Calendars showing up on smartphones (ios or android)

September 21, 2018

Outlook calendar sharing has changed in a recent Outlook patch, but what was not clear was the new impact it would have on iOS and Android smartphones. Typically a user would share a calendar out from Outlook or Outlook Web App and then follow this up by modifying the permissions that person has to their calendar. This has been improved to be a single process, in which you share permissions by adding the user to your Calendar permissions and Outlook automatically. Great, much more stream lined and we are a big fan of this.

Below is an example in which you can open the Share Calendar window and add a co-worker. Outlook automatically emails that co-worker seen in the second picture, which is all very normal and the bug will not present itself just yet. If the recipient of the calendar invite simply ignores the email and opens up Calendar, they can now open the sharer’s calendar and all is as expected and how it has been for years.


If however the user is on the newer version of Outlook, the interface will have now have an accept button at the top that if pressed changes to ‘accepting’.

This causes a signal to go to 365 and then instruct them to include that users calendar in their own calendar as a secondary calendar on all smartphones and tablets which have the 365 account for the recipient of the share. The unexpected addition of this calendar can cause havok for users as they suddenly have a hugely populated calendar on a small screen, often causing confusion as to what conference calls they are supposed to attend or reminders to do X and Y.

From our testing, we even saw a bug where the additional calendar would not remain de-selected if user did not want to view the other calendar, resulting in a frustrating experience.

The next big question was what would happen if we deleted the Calendar, as it was clearly a live calendar and and could be interacted with, what would happen? We tested this out with all of the permissions from view only to delegate, and in our testing environment, the deleting of the calendar from the iOS 11 device resulted only in the calendar being removed form the smartphone. Also worth noting if you return to Outlook and click the accept button in the invite again, it pushes right back to the phone and tablet again. It is an account wide setting and removing from one removes from all other devices (excluding Outlook).

Looking at this as a feature, and assuming you don’t get the bug where it imposes the other calendar on you at random, it is a pretty cool feature for PA’s and co-workers who want to check availability of each other while on a mobile device. Contacting MS 365 support and registering this as a bug, they couldn’t figure out what was going on and suspect this has been rolled out without the appropriate notification or even a simple email announcing the feature would have sufficed (think Clutter or Focus Inbox).
Hope this makes sense and as always, give us a shout if you need any help or advice on IT matters. We are reachable on 01296 345 000.


Posted by Kieran Donnelly