Shared calendar on macOS Calendar app

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Since few months shared calendars are gone from macOS Calendar apps (not Outlook on Mac, the native calendar app of macOS).


It's a well known bug who impact every macOS version who has been introduced this summer and was supposed to be solved soon.


I've just got the phone support for Office 365 who told me that this issue wont be fixed and shared calendar support will just be removed for macOS.


Is it true? If so it's a really big drawback in Office 365 who was just perfect for Mac users until this bug.


(And no, using Outlook isn't a valid answer for this, Calendar app is more suitable for some user and the feature was supported in the past)

11 Replies

Hi Yoann,


Shared calendars are and will continue to be accessible from the native Mac OS X calendar app. However, we are not exposing all the improvements to shared calendars via the EWS protocol, which is what that app uses. Users on the native Mac OS X calendar app will continue to be reading & writing directly to the shared calendar in the old-model of calendar sharing.


It's possibly a bit confusing because the iOS calendar app (which is branded as the same app) uses EAS, which is a supported protocol for the new shared calendar improvements.


In other words, if you accept a new shared calendar, you will see it appear on your iOS calendar app without any additional actions, but it will not show up automatically in the Mac OS X calendar app (you still need to go and open that calendar explicitly from within the app).


Does that make sense?

What's really confusing is that the shared calendar directly seen on Calendar for macOS was working before and now it's just gone…

I understand there is feature difference between EAS and EWS, but what I don't understand, is that the feature was here on macOS and isn't supported anymore.

What is still working on macOS is the delegated account, but it's not the same sharing method from OWA.

Please, could you make a formal documentation explaining how to handle shared calendar via OWA for iOS and macOS native apps?
best response confirmed by Vasil Michev (MVP)
We discovered that the Mac OS X app was requesting hidden folders when fetching list of calendars. The new shared calendars are stored as hidden folders and were supposed to be only visible in EAS & REST APIs, but we weren't explicitly excluding them from apps that requested hidden folders.

While they showed up in the EWS app, full functionality was never supported via EWS so it's possible that edits would fail, for example.

I've submitted a request to our support writers to update the calendar sharing support article, but most of them are out of town on vacation for the holidays. I'm hoping our documentation is updated in early January to reflect this.

Also, please feel free to private message me with more details on why your users want to use Mac OS X instead of Outlook for Mac - I'm curious what the deltas are.

Hello - I believe I also have this issue. Essentially I cannot (where I used to be able to) add an Office 365 shared calendar to iCal via Delegation. The shared calendars cannot be found, despite seeming to have the correct permissions. Two relevant screencaptures attached.


Any guidance would be most appreciated as Google has failed to provide a solution.




I am also interested in this.

We are developing a calendar client based on EWS. Some of our Office 365 users cannot add delegate calendars. Interestingly, trying to add these shared calendars on Apple Calendar on macOS, it also fails (see image).


Screen Shot 2018-09-24 at 16.39.17.png 

I am experiencing the same issue. Delegating a calendar in the macOS calendar app connected to Office 365 does not work because the user to delegate to is not found. This used to work fine, but does not anymore. Any hint how to resolve this is much appreciated.



Is there any new status on the original request?


A customer of mine is sharing calendars across the organization and they all use Mac and Mac Calendar.

They seem to see the invitations to other users randomly, though they cannot accept, reject or do anything about them.



Sincerely Peter

Hi Peter,


The Mac OS X Calendar application uses a legacy API (the EWS API) which does not support shared calendars. Apple will need to update their Calendar app to use REST APIs in order to view & manage shared calendars.


However, you can use the Outlook Mac client to manage & view shared calendars. We've just rolled out a major update that greatly improves the shared calendar experience. This update is currently available to all Office 365 users on Insider Fast builds, and we hope to have it available to all users by end of year. If you want to join Insiders Fast, you can follow the instructions here.


Below are some of the highlights of this update:



  • Simple, consistent sharing: You can now share your calendar from any Outlook client (Windows, Mac, Web, iOS, Android), and there's a simple set of calendar sharing permissions that are consistent across all Outlook clients. The invites that are sent out are the same format, no matter which client you send from as they are now generated by the Office 365 service rather than the clients themselves.
  • Easy to accept: All Outlook clients also have an easy "Accept" button when you receive a calendar sharing invitation. This is a brand new feature for Mac!
  • Shared calendars roam to every app: You will see the same calendars across all Outlooks as well. In the past, Mac was reading shared calendars from a local store rather than from the service, and with this update, Mac shows the same sahred calendars as you see in other Outlook applications.
  • Free/busy in Mac: In the past, you were not able to view shared calendars unless you had full read permissions. With this update, you can open & view calendars where you have only free/busy permissions. It doesn't matter if you've been explicitly shared the calendars, or you are opening the calendar of another user in your organization where you have permissions via the default organization permissions.
  • Secondary calendar sharing in Mac: As you were probably aware, in order to share a secondary calendar from Mac, you also had to share your primary calendar. This is also fixed with this update - you can share any calendar regardless of permissions on other calendars in your mailbox.

In addition to all the calendar sharing improvements above, there is some additional calendar goodness in this Mac update: such as the ability to add inline attachments to a calendar invite, create Teams meetings, or choose to prevent forwarding a meeting invite (already released in Windows & Web).


Feel free to direct-message me with any feedback!



Thank you Julia for responding.

It is supporting shared calendars to the extend that they can easily add and see each others calendars.


When they get an invitation, they can also accept it in Mac Calendar.


The only annoyance is that they can randomly see invitations to other people in the organization. I suppose that is due to the "invisible" shared folders.


I am awaiting the new rollout, it might make a change to the behaviour, even though Apple is not supporting REST API actively.


I'll talk to them about using Outlook too.




Sincerely Peter

For what it's worth, today I reinstalled MacOS Sierra 10.12 and shared calendars (in iCal, via delegation) work just fine. Your mileage may vary.




Problems arises when they see meeting invitations addressed to persons in the shared calendars, not their own.

This behaviour seems random.