Wednesday, December 6, 2017 [Tweets] [Favorites]

Month 13 Is Out of Bounds

Rob Griffiths (tweet):

But if you’re unlucky enough to be a Mac user in the month of December, 2017, then you’ll probably be seeing a lot of “Month 13 is out of bounds” messages in your Console. And by ‘a lot,’ I mean an exceedingly excessive never-ending stream of spewage…

Thousands and thousands and thousands of them—I’m getting anywhere from two to 20 per second, continuously.

Benjamin Mayo:

The plot thickens. Similar logs are generated by my iOS 11.2 iPhone, which is up-to-date. It seems like Apple patched over the Springboard crashing but the underlying calendar logic is still broken somewhere.


I’m getting this and it is causing UserEventAgent to consume all my cpu and RAM. Only solution is to set the date back until November.

William Osman:

My MacBook Pro was rinsed by UserEventAgent. Took full use of CPU and memory. I had to force quit it within Activity Monitor every ten minutes to keep laptop running.

Alexandre Colucci:

’Month 13 is out of bounds’: The official CoreFoundation ‘__CFYMDFromAbsolute’ source code is available online. You can see the new ‘ASSERT_VALID_MONTH’ define causing all the ‘Month 13 is out of bounds’ logs.

See also: Apple Developer Forums.

Previously: Rushed iOS 11.2 Update to Fix Date Crasher.

Update (2017-12-06): Stuart Breckenridge:

It’s appearing at least 20 times per second and other than disabling Bluetooth, I haven’t found a way to stop it.

Update (2017-12-08): Gus Mueller:

Wait, 10.13.2 didn’t fix the Month 13 is out of bounds problem?

Update (2018-01-01): James Thomson:

I hate to tell you… it’s January here and Month 13 is still out of bounds.

Update (2018-02-06): Zeeshaan Aamir:

After updating 10.13.3 still i am getting the same problem


Good thing: either Apple fixes it within the next week or it doesn't. In not even 4 weeks January will hopefully silent the bug.

Patrick J Mele

submitted Bug Report to Apple Developers

Month 13 snout of bounds has not disappeared on 1/1/18 at 7 PM.


Also associated with Alfred.3, LCDDaemon, UserEventAgent, DefautFinder X, PathFinder, task gated, etc, etc

@Ron Yep, I’m still seeing it on my Macs, too. :(

Also seen with Microsoft Outlook. Working with AppleCare Enterprise.

Does not happen on a freshly installed machine.

"Month 13 is out of bounds" seems to have stopped (Jan 2, 2018, 3:45 PM). Perhaps it is the new month (January) or the fact that I shut down and then restarted my iMac. Other error continue to abound in Console.

Patrick J Mele

Month 13 is out of bounds has stopped in console errors as of Jan 1 2018 for me as well calming my cpu usage down

I’m still getting them. :(

10.3.3 Beta allegedly stops this.

It stopped for me in early January - anyone else still seeing it?

I’m still getting reports of it from customers.

I just upgraded to high Sierra and got it while debugging my app. Here is the full log:

2018-01-19 10:45:16.032929-0500 Rc²[27493:433236] Month 13 is out of bounds
2018-01-19 10:45:16.040346-0500 Rc²[27493:433236] Month 13 is out of bounds
objc[27493]: Class FIFinderSyncExtensionHost is implemented in both /System/Library/PrivateFrameworks/FinderKit.framework/Versions/A/FinderKit (0x7fffb4ca0b68) and /System/Library/PrivateFrameworks/FileProvider.framework/OverrideBundles/FinderSyncCollaborationFileProviderOverride.bundle/Contents/MacOS/FinderSyncCollaborationFileProviderOverride (0x10f72dcd8). One of the two will be used. Which one is undefined.

Apple escalation assures me this is fixed in macOS 10.13.3 and later, which was just released.

Since the problem stopped for me in early January, I have no way to test. Anyone still seeing it should see if the update fixes it and let us know.

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