Where do current OS X versions store local user calendar data?

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Level 1

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Where do current OS X versions store local user calendar data?

My partner has an M1 MacBook Air running OS X 15.7.3. A few months back, the entire contents of her calendar (stored in iCloud) disappeared. All past and future events were gone. We requested support from Apple, who walked us through the usual steps of restoring from Time Machine, but without success. The problem was escalated to Apple Engineering, but we never heard anything from them.

As my partner had now lost trust in iCloud, we set up her machine to use a local calendar only, knowing that we could ensure we had backups of the local file in Time Machine and ArqBackup.

Today, her calendar is empty again. Checking the backups in Time Machine and ArqBackup, I find that "~/Library/Calendars" contains nothing that looks like a calendar data file. There's:

Calendar Sync Changes
Calendar Sync ClientID Conflicts.tmp
Email Cache.plist
Incoming
NotificationIconCache

plus an ancient .icbu backup file from several years ago, but that's all. The folders are mostly empty; the icon cache is what it says. Restoring "~/Library/Calendars" from either Time Machine or Arq does not bring back the missing events.

So wherever Calendar data is getting stored, it certainly isn't "~/Library/Calendars". Where do modern versions of MacOS X store local calendar data?

Posted on Feb 10, 2026 7:33 AM

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Answer 1

Top-ranking reply

Strontium90

Level 5

5,539 points

Feb 10, 2026 7:56 AM in response to mongoosenyc

Look in ~/Library/Group Containers/group.com.apple.calendar

The local calendars are stored in sqlite databases which is often a challenge. Consider periodically exporting your calendars to flat files for more reliable backup.

Hope this helps

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Answer 2

mongoosenyc Author

Level 1

28 points

Feb 11, 2026 2:50 PM in response to Old Toad

Yes. As I said, that was the first thing I tried, but unfortunately it didn't help. I think that directory was once used for Calendar data, but Apple now appear to have migrated the files that matter to:

~/Library/Group Containers/group.com.apple.calendar

(certainly on all the Macs that I was able to inspect, the Calendar databases are now stored in that directory).

I was able to resolve the issue by restoring that directory from backup.

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Answer 3

mongoosenyc Author

Level 1

28 points

Feb 10, 2026 5:24 PM in response to Blaskowitz

Thank you (and @Strontium90). `~/Library/Group Containers/group.com.apple.calendar` turned out to be the location I needed.

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Answer 4

Feb 10, 2026 7:54 AM in response to mongoosenyc

That file list looks incomplete for a working Calendar setup. You are definitely in the right directory (~/Library/Calendars), but you are missing the critical database files.

You should be seeing files named Calendar Cache, Calendar Cache-wal, and several folders with long UUID names (e.g., A1B2C3...). The "On My Mac" data usually lives inside one of those UUID folders in a subfolder called Events.

If those files aren't showing up in your backups, check two other spots where macOS sometimes sandboxes data:

~/Library/Containers/com.apple.iCal/Data/Library/Calendars
~/Library/Group Containers/group.com.apple.calendar

One thing to watch out for with third-party backups like Arq: since the main database file is literally named "Calendar Cache," some backup rules might automatically exclude it thinking it's temporary junk data .

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Answer 5

MartinR

Level 7

25,480 points

Feb 11, 2026 10:25 AM in response to mongoosenyc

The internal locations of the Calendar and the Contacts databases are obscure and have changed over the years.

For that reason, the best practice to back up your Calendar is to periodically export it to a Calendar Archive (.icbu file) and tuck the file somewhere where you keep backup copies.. Ditto with Contacts (.abbu file). If your calendar or contacts database ever gets corrupted or deleted at least you can re-import the last Archive you made.

Longterm, however, it's a good idea to periodically export Calendar data to an .ics or .txt file; and Contacts to Vcards. The reason is that there have been changes to the Calendar & Contacts databases over the years that have made previous archive files (.icbu, .abbu) unusable with a later version of the app (at least, that has been my experience more than once). The .ics, .txt and Vcard files are universal.

Bottom line, I actually recommend using iMazing to backup iOS devices. With iMazing you have access to nearly all your iOS data ... and the Calendar can actually be exported directly to a .txt file that can be used with nearly any application. It has saved me more than once.

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Answer 6

Old Toad

Level 10

217,062 points

Feb 11, 2026 2:43 PM in response to mongoosenyc

Have you tried restoring the Users/Home/Library/Calendars folder?

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