Calendar app in macOS Monterey 12.0.1 freezes when changing dates

I'm having _exactly_ this problem as well. And the same repeatability of the issue -- if I deselect the outlook calendar (but keep the gmail calendars), issue goes away and calendar app runs fine & snappy. I reselect to add the outlook calendar and the issue returns. (At least this bug is repeatable!)

Hello Sean-DC,

Thank you for participating in the Apple Support Communities! We understand that the Calendar app isn't behaving as expected with your Outlook account after upgrading to macOS Monterey.

We appreciate you sharing the steps you've taken to isolate the issue to a specific account and would like to further rule out any software or user-related causes next. If you enable the Outlook account and start your Mac in safe mode, is there any change in behavior?

How to use safe mode on your Mac - Apple Support

Also, do you have another user account you can log in to and test your Calendar with? If not, let's create a user account for testing:

Set up users, guests, and groups on Mac - Apple Support

Let us know what you find.

Take care.

I'm having the exact same issue with Monterey on a new M1 Pro chip MacBook Pro 14". I have iCloud, Gmail and Microsoft Exchange accounts connected to Calendar. A couple of additional observations:

1. As others have described, when I am in Day or Week view and page to the next screen, my Calendar hangs for 3 - 14 seconds while it displays the beach ball and eventually paints the page.
2. Interestingly, if I am in Month or Year view, it scrolls seamlessly and all of the data is there.
3. If I turn off WiFi and work completely offline, there is no change for the better or worse in any of the views.
4. Booting in Safe Mode has no effect.
5. If I deselect the Exchange account, Calendar will page seamlessly in all views.
6. This MBP replaced an 8 year old MBP (late 2013 processor). I set this one up from that machine's Time Machine backup, so they are essentially identical now.in how they are set up. I have them side by side with the old MBP running Big Sur and it will seamlessly page through any Calendar view.
7. If I have the same issue while online or offline and if scrolling is seamless in Month view, but hangs on the Day or Week, this CANNOT be an Exchange server issue. The data is clearly local and renders perfectly in Month view. This is an OS issue (Monterey).

Thanks!

Hi Sean-DC,

Thanks for getting back to us with the results. Since you're still experiencing the issue and it didn't start until after you upgraded to macOS Monterey, we'd like to have you get in touch with Apple Support for a closer look. You can contact them using the link below:

Get Support

Take care.

+1

Also have this exact same issue since upgrading to Monterey. Apple calendar app is now super-slow and freezes for several seconds with beach-ball cursor when switching between weeks. And only happens when my Exchange calendar is visible.

I'm getting exactly the same issue, changing week with Exchange calendar is really a problem as it takes extremely long. I use my Mackbook for business purposes and this is seriously impacting my performance.

It all started with Monterey 12.0.1, before it's always been super good.

I've seen several threads reporting this, and it looks like a huge thing no, so I hope this is solved soon. After 10 years avoiding using Outlook for Mac, I believe I don't have any option now :(

It's related to Microsoft-hosted calendars, but it's not a Microsoft issue; Apple Calendar with Exchange continues to work fine in Big Sur (and other versions I'd suspect as well). Apple broke something in iOS 15.1 and Monterey 12.0.1.

Thank you for reminding me to also confirm similar behavior on iOS 15.1 devices.

I wonder when they'll get around to fixing this. I'm tempted to switch over to Outlook. Has anyone else made this transition?

I do have Outlook installed on my M1 Pro MacBook Pro 14" laptop and it works flawlessly. As I've stated in my earlier post, I also have my 8 year old MacBook Pro still running Big Sur with ZERO lag when paging in Calendar, with the exact same accounts as my brand new MacBook Pro that has a terrible lag between pages in either Day or Week view (no lag for me in Month or Year view). Those accounts (on both laptops) are: iCloud, Gmail and Exchange. This is definitely a OS issue with Monterey, not an Outlook or hardware issue.

I have the same problem mentioned; additionally, Outlook-based calendar invites when accepted through the email do not post to my calendar anymore (and of course once you accept the email goes away), yet the inviting party receives the acceptance. Very difficult situation--Apple!

Hi MichelleT18,

This problem is now being noticed widely. It is NOT related to the issues (safe mod / users) and that won't make a difference.

It is something to do with O365 accounts. If you have one (or more) the whole of calendar is impacted.

This was not the case with prior versions of MacOS so it is a bug in the Monterey version.

AB

+1

This is connected with having several calendar servers connected, in particular MS Exchange.

In my case, I have two Exchange calendars activated on top of my iCloud calendar. If I de-activate the two Exchange endpoints, the calendar goes back to being as fast as it was under Big Sur – very fast.

Ich habe das gleiche Problem (Kalender mit exchange O365 und Google), sowohl auf dem Mac Book Air M1 und dem iPhone 13 Pro. Ich kann so nicht mehr arbeiten!!! Ich habe mir für beide Geräte einen fremden Kalender (Kalender 366 für Mac und MiCal für iPhone) aus dem App Store gekauft und damit funktioniert alles korrekt wie es soll.

Ich denke, es kann daher nur an Apple liegen.

The problem also annoys me. I just deleted the account again and added it back, but it takes several seconds with the Exchange connection. In addition, no appointment opens from time to time. After closing the calendar it's working again.

Please fix this problems quickly!