Calendar very slow with macOS Monterey

I have the exact same issue on my MBP and iPhone Calendar. I think this slowness is with any Calendar (Exchange, iCloud, etc.) that has been used consistently and over a long period of time, or is generally loaded up with events. For instance, I notice that weeks where I have less appointments load a little more quickly. But if I turn off the calendar with the most events (in my case, Exchange), Apple Calendars returns to its normal reliable and snappy self. I was going to wipe my MBP and start fresh, thinking it was a backend Calendar data corruption issue after the upgrade, until I noticed the exact same frustrating and lagging behavior on iOS. I had no issues or problems at all with Apple Calendars until the most recent iOS 15 and macOS Monterey. I do see attempts at additional integration with Calendars after these updates, such as the "Join" feature for videoconferencing calls. But these new "features" don't work as expected at all and are not helpful. Apple screwed up. They pulled a Microsoft move. They tried loading up other items in the background (like the numerous Outlook plugins that destroy Outlook efficiency) and killed the Apple Calendar's very noteworthy, reliable, and desirable efficiency. I'm seriously considering moving back to Outlook calendars (I know, I feel sick to my stomach even saying it).

Please Apple, fix this!

Or at least give us the ability to turn off these new backend integrations and "features" that are quite obviously not fully baked.

I chatted into Support just now since there was no update on Calendar, and wound up on the phone w higher level. One intriguing possibility: I never bothered to migrate from @me.com to @icloud.com, so my calendar is still pulling from @me. Support thought that might be the problem, since all @me's are now aliases, not real accounts. The interesting piece was, we tried over and over to switch my primary icloud account from @me to @icloud, and were unable to - he's now escalating both topics to engineering.

If anyone else is still running @me, see if you can delete and switch to @icloud, and if that helps Calendar?

Same here.

It's slow when you are using an Exchange calendar and you are in week o day view.

Waiting for a fix.

L

I have the same exact issue with macOS 12.x Calendar app when Exchange account(s) are added.

macOS 11 and prior worked fine.

Currently the Apple Calendar is barely usable.

I submitted a support ticket with Apple about a week ago, got no reply.

Everyone please submit support tickets using the Feedback Assistant.

I think it depends on the amount of data stored within the calendar and not the type of calendar (Exchange, Google, etc.).

I did not find out any dependency yet except the data and how many people are invited to a meeting.

Obhájce completelly samé issue with cal. I have subscribe iCal calendar and week to week scrolling needs more than 30s. Starting calendar 10s on MacBook Pro 2018.. I console I a lot of errors with non initialized objects/ variables. Maybe should be associated with new reimplementation of app to swift ui

I have the same problem after the upgrades to 15 and Monterey. PAINFULLY slow and this points to Apple's Exchange API code being faulty. Given the problems seem to parallel each other it might even be the same code family running on both OS platforms.

Also the email API has a similar delay but not anywhere near as severe.

Apple needs to fix this or calendars are almost unusable.

I don't think the problem is with Exchange. I also have the Fantastical calendar app on my Mac, and that doesn't have any problem at all with syncing with Exchange, it's as quick as it ever was. Apple Calendar has slowed to a crawl.

Several people have said in this thread (and elsewhere) that they have been in touch with Apple support and made them aware of the issue and of these threads.

When I first found the problem, I put in a detailed report using the "Feedback" app on macOS (/Applications/Feedback Assistant).

aps

I also think it is the "amount" of data, if you remove Exchange then this is prob removing ~85% of the data from the calendar app.

If it was just Exchange, I would think my @iCloud.com and @gmail.com events would load (only delaying my exchange events).

Really need a fix as this is my one calendar on my iOS devices

It would be interesting to know if someone out there works for a company using GMail (assuming there are many events per week), and if they are seeing the same issue when syncing their Google Calendar to iOS and/or Monterey

I got the same issue. it might be related to the new feature that adds a "join" button to zoom meetings.

My work calendar has a lot of zoom meetings. Whenever I go to the next week, it takes 3-5 seconds to load the events. And this is on a 16 core Mac Pro with 96 GB of RAM. In macOS Big Sur, this was instant.

I moved off calendar last week. Downloaded alternative until they get this fixed. Can't afford to be late to meetings or calls because Calendar has frozen and I can't see any of the contact/link info.

I have many Exchange-sourced events/meetings on my calendar and quite a few iCloud ones. I have never had a missed event.

The only thing I've experienced with this problem is slow rendering - nothing else. Calendar is still reliable.

As an aside, I use a great little application called "InYourFace" that faithfully "alerts" me by flashing the screen (actually, both monitors on my dual-monitor system, and in every space I've defined). You can define which calendar or calendars you want it to watch. Works for any event in your calendar.

Again, the Calendar problem only appears to be one of rendering - nothing else. Having said that, it might be a nicer experience to not have this very annoying delay.

Hi.

Are you saying that you have the issue such that when you remove the gmail calendar, things get fast again? Or are you saying that you have mixed calendars with both Exchange and gmail and when you remove the Exchange calendar sync, things get "normal" again?

I'm having the same issue.

Exchange calendar seems to cause the problem.

It happens the worse in weekly view.

Daily and monthly is tolerable.

Apple please fix this I switched to calendar app because it is so fast and simple.