My Mac Apple-Calendar went berserk-I need help!

Hello Apple experts,

I was seemingly innocently syncing (via USB wire) my Apple-Calendars between my Mac-Mini (Ventura 13.5.1), and my iPad (version 16.6). Things ran totally amok here.

The iPad Calendar is only modestly messed-up, but the Mac-Mini Calendar is totally messed up. The data portion of the Mac-Mini Calendar is totally corrupted.

I do have back-ups available. Is there some sort of way I can load an older copy (via back-up) of the data-portion of the Mac-Mini Calendar, and replace the latest, messed-up data-portion, with this older (good) data-portion?

Any other decent ways to approach this problem?? I really do not want to manually reconstruct my Calendar entries. I don’t even know if manual-reconstruction is a feasible thing to do.

Any tips to get me “reset” here, Calendar-wise, would be appreciated !!

This is a Ventura issue I have seen since Ventura betas. I know others with it. Sonoma Public Betas also. I have spent hours trying to isolate it with no success, and hours w/ Apple support.

If you have been syncing w/ Ventura for some time with no problem you can try the following, otherwise I would go back to Monterey (where I am).

You can restore the desktop Calendar w/ Time Machine. The data is hidden in User/You/Library/… If you need the exact path to the Calendar data in ~/Library, I can look it up again.

Then you can overwrite the iPad Calendar by syncing with the “Replace Contacts” and “Replace Calendars” boxes checked at the bottom of the “Info” panel of the Finder syncing page.

I am presuming you are seeing a lot of repeating Events excessively repeating, as often as every day, etc.


Thanks for your note.

Yes, I am seeing the same thing you are describing. As it happens, this was the first time I have tried syncing Calendars with Ventura (because, I just recently converted all home Macs with Venture 13.5.1).

To me, this is totally unacceptable, with regards to Apple software engineering not fixing this sooner.

I am tempted to get things fixed (I hope) and return to good Calendar data, and then I plan to switch to BusyCal, where the likelihood is if one does have a problem/bug which needs fixing, this company will be more responsive.

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I have contemplated other calendars, but none of them sync locally (that I have found).

The path you want for restoring is simpler than I remembered:


I think, strictly, you may only need the “*.calendar files,” but I would just grab the whole folder.

I am assuming you have or know how to “unhide” ~/Library?

Yes, I know how to find the /Library. Thanks.

Also, thanks for the additional

Obviously, not everyone has this problem, but many do. I have seen reports in the Apple discussion groups that go back several OS versions. I’ve gone over and over what could be different in my setup, that could cause it.

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ok, I am having some difficulty finding /Library/Calendars on the backup.

Can you help me out here?

I am not using Time-Machine, but rather, a CCC backup (Carbon Copy Cloner)

It’s in ~/Library/Calendars/, not /Library/…

So it should be in the Library that sits at the root of your user directory, not the root of the disk.

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Thank you for your input, Simon.

I am still sorting through everything, to resolve this issue, although I’ve taken a break, and hope to return to it all, soon.

I will let everyone (on this thread) know how it all went.

Hello everone,

An update: I did restore my uncorrupted Calendar data via a recent backup. Whew !

Thank you - to everyone on this thread, who helped me out here !!

And now, for a few well-timed complaints against Apple software engineering:

  • For some time now, I have abandoned the Apple-Mail Client because of some fundamental issues (like mail messages would simply get “lost”), in favor of Mimestream, which works great for me, and I now pay the subscription price, but it is worth it to me. (BTW, Mimestream is at this time available only for gmail accounts, and that is what I have, so this is not a problem for me.)

  • Now I am faced with migrating from Apple-Calendars to BusyCal (another 3rd-party vendor with a price). I am not sure about implementing this option at this point. However if I did choose to go with BusyCal (or an equivalent vendor) away from Apple-Calendars, then this will be the 2nd time I have had to abandon basic Apple apps.

  • In the past, my syncing of Calendars and Contacts were always via USB wire, and based on local copies residing on my various Apple devices (that is, Mac and iPad). For some time now, the Contacts syncing simply did nothing, and did not sync at all. An annoying problem, but not a show-stopper. I felt could live with that problem, but now, look at the overall picture here.

  • So, what does this all say about Apple built-in software provided as a part of the overall macOS? Apple always hypes their latest macOS as being the greatest thing since (fill in the blank here). Yet fundamental bugs remaining in some of the oldest, built-in apps are preventing even basic use of these apps. Come on, Apple !! You should be doing better than that !!

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I think in this specific case, it’s just that Apple has determined local sync via USB is something they’re simply no longer interested in. Hence, no resources get devoted to diagnosing and fixing issues. In that sense, the latest and greatest macOS perhaps offers lots of improvements and fixes, but I would doubt any of them attack issues related to USB syncing to local devices. In Apple’s view, we should all be well-behaved and finally migrate to using iCloud. “We think you’ll love it”. :wink:

(And don’t get me wrong. I don’t need convining there’s a reasonable use case for local and wired syncing. I just claim Apple disagrees. And since it’s their OS…)


Yes, I agree with you, basically. A cynical person might say these bugs are being introduced sort of intentionally, to entice/convince “old school” people like me, that I need to “get with it” and trust having all my data in the cloud. (I do have some of my data in the cloud, but I am trying to be careful in this respect.)

But still, I feel like there is no good excuse (for Apple) to be introducing bugs into once well-established software (such as local-syncing), when updating their macOS software. I feel like Apple (by now) should have a good set of regression-tests to help confirm they have not introduced new bugs.

Anyway, I think you’re correct, in that Apple does not consider this particular stuff (that I still care about) important enough to worry about. This is pretty disappointing, for me.

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This worries me. I have a desktop 2018 MacMini and a laptop 2017 MacBookAir, both now running Monterey. The Mini can run Ventura but the Air cannot. Does this mean that I can’t update the Mini to Ventura without messing up my Apple Calendar? I use both machines and need them to be running the same Apple calendar, which they are now doing through iCloud. I’d greatly appreciate some help.

As far as I know, the major problem I was seeing (with respect to syncing Calendars) was due to (a) recently installing Ventura on my Mac-Mini, and (b) using local-syncing, via a USB-wire.

I am not absolutely sure of the following, but:
I believe iCloud syncing would work for you, but you might want some verification of this fact from some other person(s) who has/have experience with what you want to achieve.

Also, regardless, before trying the new scenario, I would highly recommend having a good, recent back-up which includes a decent, uncorrupted Calendars folder (which resides in the Library).

But they shouldn’t, because:

  • It’s hard enough to write software that works when you’re trying to make it work.
  • It assumes that everyone who would have any access to the code would be sufficiently ethically challenged to put effort into making software work worse, potentially introducing even more bugs into the process.
  • It would open Apple up to legal liability and reputational damage if proof ever leaked out.

To paraphrase Hanlon’s Razor: “Never attribute to malice that which is adequately explained by unmaintained code.”

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At least in our household these problems have only popped up when syncing via USB between Mac and iPhone. For other systems where the sync uses iCloud Calendar we have seen no such trouble.

Also, I believe USB is unrelated. If it’s local sync it will likely cause issues regardless of USB or wifi because it’s a software problem related to local sync (as opposed to iCloud) — it’s independent of hardware interface.

Hi Adam,

Yes, I agree totally with you. I was trying to be a bit amusing. Maybe I failed in this attempt.

Sorry, I’m a bit sensitive to that because there are so many damn conspiracy theories floating around that I tend to come down hard to stop them. :slight_smile:

Yes, no problem. I did not even think of that aspect.

In thinking about it, I believe I was more snarky-sounding, than amusing.