Fix iOS 15.1 slow Calendar issue

fix laggy Calendar app in iOS 15.1
fix laggy Calendar app in iOS 15.1

Apple has rolled out the public iOS 15.1 with some added improvements and bug fixes over the previous iOS 15. But with the fixing of previously known issues, the iOS 15.1 has its own set of bugs that are making the iPhone users pretty much completely unable to use certain apps. One of the most commonly experienced bugs in iOS 15.1 is the lag in the Calendar app. The bug makes the Calender app extremely slow to respond and scrolling through meetings is buggy.

The slow calendar app is not the only issue. The users are reporting that the set appointments are also appearing on a wrong day and sometimes jump around to correct themselves. A couple of users have also said that along with the Calendar app, the Calendar widget is also affected by the bug, making it completely impossible to use the Calendar services by every means. If you are also one of those users who are experiencing the same issues with the Calendar app on your iPhone running iOS 15.1, then this fixing guide will get covered by providing you with the solution to this bug.

How to fix if Calender app is slow to response

The abnormal and slow behavior of the Calendar app has so far been diagnosed as a bug in the Calendar app itself. And here are the possible ways to solve the issues.

Fix 1: Restart the phone

The very first and most common thing to do when struggling with any kind of unusual activity by the software is to restart the whole system. Similarly, you can begin by giving a good restart to your iPhone. To restart the iPhone, press and hold the Power button and volume up button simultaneously until the Power off slider appears. Now, swipe the slider from right to left to turn off your phone. Once, the phone is completely off, press and hold the power button until the Apple logo appears on the screen. Let, the phone boot up.

Now, open the Calendar app and see if the issue is solved or not. Some of the iPhone users reported that a restart solved the issue. But there are still a majority of iPhone users who said that the Calender app initially works just fine but after using it for a couple of minutes, the situation gets back to what it was before restarting the phone.

Fix 2: Check for Software Update

The next thing to look for is if there is any software update pending on your iPhone. The issue has been experienced by almost all the users after they have upgraded to iOS 15.1. If Apple has acknowledged the Calender issues, then there are possibilities the company will deliver a software update to the users. To check if there is any update available, go to Settings > General > Software Updates. If the phone shows any pending update which is to be installed, go ahead as per the on-screen instructions and install it.

Fix 3: Remove Exchange account and use iCloud

Most of the iPhone users who are facing the slow and abnormal calendar issue in iOS 15.1 have reported that the issue persists in the Calendar app when they use the Microsoft Exchange account. When the users switched to an iCloud account, the Calendar app was working perfectly fine. Based on this, you can also try this by removing the Exchange account from your iPhone, and using the iCloud instead.

To remove Microsoft Exchange account:

  • Go to Settings > Calendar > Accounts on your iPhone.
  • Now, select the Exchange account and tap on Delete Account.
  • Tap on Delete from my iPhone option to confirm the removal.

Set iCloud account in the Calendar app

  • Open Settings and tap on your name.
  • Go to iCloud and make sure the Calendar toggle is switch on.

Open the Calendar app now and see if the app is working fine or not. If you are OK with the iCloud account on the Calendar app then keep it as it is. But there are many users who use the Microsoft Exchange account for daily life and for those users there is no sense to use the iCloud account.

Fix 4: Downgrade to iOS 15

If you are not OK with using the iCloud account on the Calendar app, then you’ll either have to wait for a new update for iOS or you can downgrade to an older version where there was no issue with the Calendar app. As per the users, the iOS 15.0.2 was working fine and there were no issues in the Calendar app. To downgrade from iOS 15.1 to 15.0.2, I have linked a very detailed how-to guide on the same. Make sure to read all the steps carefully as they can cause software damage to your phone.

Edit (26 Nov 2021): Apple has blocked the downgrades from iOS 15.0.2 and 15.1. Click here for more info.

Fix 5: Contact Apple support for resolution

Lastly, if there is no option available to solve the issue, the only open door is to contact Apple support. Explain the whole issue to the Apple representative and they will guide you with the instructions if there will be any possible solution to the issue.

Do not Reset your iPhone

Many of the iPhone users have reported that when they talked to an Apple representative on Apple Support for the resolution of the whole Calendar app issue, they asked the users to try a reset of their iPhone. But as per the experiences of the users, resetting the iPhone didn’t work for anyone. It just made them lose their data.

Bottom Line

So these were the possible fixes to the issues that many of the iOS 15.1 users are facing with the Calendar app. The issue is relatively new at the time of writing this fixing guide and as new possible fixes to the issue. I am hoping this fixing guide was helpful for you and if it was, please consider sharing it with the needy ones in your circle. Also, if you have any questions, suggestions,s or new fixes that worked for you, please share them in the comments below. I am eagerly waiting for your valuable comments.

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Posted by
Bhanu Pratap

Hi! I am Bhanu Pratap, co-founder of Yorker Media Group. A die-heart fan of tech and keeps track of every little happening of the same. When not writing, I usually keep myself busy on YouTube making and exploring new and awesome tech content.


    1. There is no resolution in KT’s post link but go and say you have the same issue. I’m sure Apple is well aware of it by now.

  1. ” I have linked a very detailed how-to guide on the same”


    1. Apple has now blocked any downgrade if you are on iOS 15.0.2 and iOS 15.1.

  2. I’ve been having severe lagging issues since I installed 15.1 in October, tried most suggestions, nothing worked. I just decided to see if deleting recurring meetings might help. I had an invitation to a weekly zoom meeting on my calendar w/link to zoom log in. I delete this recurring weekly meeting and so far the lag has disappeared. Not sure why this would make a difference but I’ll keep checking and post again in a few days w update on responsiveness.

  3. I was experiencing the described issues in the native iOS calendar app, related to my office exchange accout, that appointments where not showing or showing at wrong time, length or caption when I was navigating through the days to come and back – for minutes, until it was stabilizing, and only until I was navigating again to another day of the week.
    I was using the outlook calendar during all this time, and was checking periodically in the native iOS calendar app, to see if the issue is solved.

    This morning, after updating to iOS 15.2, i cannot reproduce it anymore – the issue seems to be solved 🥳

  4. I just upgraded to 15.2.1 and that seems to have resolved the issue.

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