Unable to sync Calendar App after iOS 18 update

I tried a lot of solutions - this worked for me. Thank you!!

You have no idea how badly I wanted your solution to work for me! Sadly, I must report it did not. Here is my longwinded reply. Let me first say that both my iPhone and my iPad use the EXACT same settings with the only difference being the OS versions. iPhone does not work for calendar - works for Contacts; iPad works for both Contacts and Calendar.

Here are the accounts that I have:

My main account is the Destcom, which is my work account. The Gmail is my personal account that I only use for email and nothing else. The others are the same, email only. The iCloud I use for nothing related to email, contacts, or calendar.

My gmail account shows me this, and note the options. Showing this just to show the options for contacts and calendar are toggled off:

This is my main account; you will see there are NO options to toggle contacts or calendar:

However, for more years than I can remember, I've always synchronized my contacts and calendar through iTunes, and this is the setup I've had forever:

There is an obvious connection between iTunes and Outlook since all my contacts update correctly. Without reverting my phone back to 18.1.1, I can only assume this might be an OS version issue. I might possibly try doing this very thing this weekend, but it's always a pain to me when I've had no issues up until OS18.

Me, too! I have a “New” iPhone 13 which is not even a year old and …

Apple Customer Support actually misinformed me by instructing me to do a Software Update 18.0.1 and DID NOT warn me that I would loose my CONTACTS and my CALENDAR.

Now, I desperately need Apple Customer Support which appears to be non-existent to recover my CONTACTS and my CALENDAR.

Same issues for me. Now, I am so very upset as lost ALL my Contacts and ALL my past present and future Calendar appointments simply because without any warning of the consequences was I instructed by the Apple Customer Support “Lisa” to do this UNACCEPTABLE Software Update 18.0.1 😭

I DID have success with contacts, finally. From settings / contacts / contact accounts / exchange, uncheck contacts. Then force a reset of the phone and when it comes back online navigate back to the same place and re-check contacts. THEN on the contacts settings scroll down and change default account to exchange. Now when you go to contacts / lists you should see exchange and your contacts populating. I’ve got 3300 contacts it was fun to watch the number of contacts grow until it was done and now I’m ok. While the calendar issue is SO frustrating and apple support acts like I am the only one with the issue, It just has to be an ios18 issue and fingers crossed it will get resolved with the new AI update at the end of the month.

I had the same problem after having to get a replacement phone (and update to ios 18). I just solved it by going to the calendar on my phone, clicking on "calendars" and at the top of the list of calendars was a "verify account" line. I clicked on that, and it was all I had to do. Went back to my PC and hit refresh, and I found it immediately matched my phone.

Hope this helps!

My calendar is having similar issues. (IOS 18.0.1 Iphone 16)

I turn it on, and it doesn't even know what day it is. It thinks it is October 1 when it is really November 10.

I add an event to my calendar, and it does not appear. But when I search for it, it comes up in the search.

When I delete an event and "all future events", it deletes past events as well.

It is behaving as though my calendar does not know what day it is. I click on a day with a colored dot, and it does not show me what is there.

This phone is brand new, and not being able to use my calendar to reliably track my appointments is crippling.

Similar issue with everyone here.

Have been syncing my Outlook contacts and calendar from my Windows PC to my iPhone successfully for years.

Updated to iOS 18.1 and can no longer sync even after unchecking SYNC CALENDARS, checking it, and overriding iPhone several times.

Simply does NOT sync any more.

Has ANYONE had any success with this?

My reply was removed due to the version I am using for my iOS, so I won’t mention it. I researched and looked for the default calendar anywhere, and I do not have that option.

Same here. I quit all calendars on devices thinking they would update. Not only no sync now I have lost dates.

I don't see any reply from Apple. Am I missing it?? Same issue. Impacting my business

I logged into my google calendar via web browser and then went back in via the app and it had synced everything.

haven't tried to add any events yet to see if it automatically syncs.🤷🏻

Same problem. Moved from my old IPad Air 2 to new IPad Air. IOS18. All calendar entries transferred ok but new entries do not show up on my Google calendar.

Me too, Apple 12 Pro max calendar is useless, Apple please fix this!!!!

Just looked at what you mentioned and have no verification notice anywhere. Glad you solved yours!