Where does Calendar keep its caches?

I finally found the cache.

I did spend time searching the Containers directory but many of the likely named folders had no cache contents and deleting the contents of those I found did not solve the problem.

~/Library/Containers/com.apple.CalendarAgent/data/Library/Caches/com.apple.CalendarAgent/

and

~/Library/Containers/com.apple.iCal/data/Library/Caches/com.apple.iCal/

as well as the 3 files ~/Library/Calendars/Calendar Cache*

were the only ones I found.

~/Library/Containers/com.apple.CalendarFileHandler/Data/Library/Caches

~/Library/Containers/com.apple.CalendarNotification.CalNCService/Data/Library/Caches

~/Library/Containers/com.apple.iCal.CalendarNC/Data/Library/Caches

and several others were empty anyway.

I decided to search ~/ using grep for the ID of one of the calendars which kept reappearing. The first couple of times it failed after getting into a never ending loop but after I'd removed the circular referencing links which caused that (which were remnants of a remote access tool) and waiting 48 hours for the script to finish I found most of the results in a very long list pointed to the same place (but via different sets of links).

~/Library/Application Support/SyncServices/Local was the culprit. After deleting that package and the Calendar and CalendarAgent caches the old calendars no longer reappear. Both the list of calendars in Calendar.app and the sub-folders of ~/Library/Calendars only have the actively used calendars.

I've managed to make some progress but still can't find where the cache is stored.

If I delete the calendars and then delete their subfolders but don't delete the cache files then they don't reappear. If I delete the cache files they all come back which means the data must be stored somewhere else.

I would just leave it at that but still use iTunes to sync these calendars with an iPhone and the list of calendars in the iTunes "Sync Calendars" section still has the full list of calendars even though the old ones don't exist on either the iPhone or the Mac. This can get very confusing as the number of non-existent calendars in the list outnumbers the real ones and for some, the same name appears twice.

Thanks for the suggestion but unfortunately it makes no difference. I've been through the whole process in safe mode with several reboots. After deleting the 3 cache files ("Calendar Cache", "Calendar Cache-shm" and "Calendar Cache-wal") and rebooting all of the old folders are recreated (probably by CalendarAgent as this happens before Calendar is opened) and all the old calendars are displayed in Calendar when I open it.

As an experiment I decided to delete the whole Calendars folder from ~/Library after stopping CalendarAgent. When CalendarAgent started again it recreated the folder and the default calendars for a new user which I'd expected.

The unexpected happened after a reboot when all the old calendars came back. I think this only happened when I opened Calendar.app as the contents of the folder looked static for a few minutes before that.

Therefore the information must be coming from another folder but I can't find anything in ~/Library/Caches which looks as if it might be related to Calendar ... nor in Application Support.

This user syncs with an iPhone but syncing is done using iTunes and a USB cable and the iPhone has not been connected at any time since I started the clean up. As far as I am aware the only iPhone data stored on the Mac is a set of backups taken before each sync.

These old unwanted calendars are not on the iPhone although some of them been in the past.

There is no syncing with iCloud.

Thanks.

Unfortunately, this file contains just two pieces of data which are locations added to events a couple of days ago (in an active calendar). The file timestamp is also from a couple of data ago which was probably when the last sync was done, but the old calendars have reappeared at least three times since then.

However, the Containers folder is not a place that I've looked at in detail as I didn't know what it was (still don't) and the files at slightly higher levels are mostly binary so I can't tell what's in them, but deeper levels look hopeful. I'll see what else I can find in the Containers folder when I've got more time later. There seems to be a collection of caches in ~/Library/Containers/com.apple.corerecents.recentsd/Data/Library/Caches/com.apple.CalendarAgent/ which looks promising.