Month 13 is out of bounds – one of the funniest computer errors ever

Month 13 is out of bounds, this funny error-message first appeared in December 2017, on the device log & console of a lot of macOS devices. The error has been reported by a lot of different applications, but mostly by third-party applications, thats why i think, that there is/was an error with the communication of the kernel and these applications!

So these applications thought that the December, would be Month 13. To manage processes, any application needs an timestamp and the most applications also need the date, so that they can work correctly.

The error appeared whenever these applications where running and the only problem with that is, that sometimes this message was displayed multiple times in a second. Interesting was, that this error mostly happened, whenever the cpu and ram usage was high.

The error message was also displayed (@ my iMac) in the beginning of January 2018, but at this time it was not as funny, as in december.

Why? Because its the 1 month in the year and it would be possible, that the 13 months would stand for the months, since the application has been installed, but it was not.

When you observe other errors and log messages, you can see, that sometimes RAM errors happen, while the Month is out of bounds error, is posted. An code error of the applications is not logic, because on my iMac, over 20 applications displayed the error, this makes it pretty clear that the error is not caused by an code error, of any third party applications developer.

The normal system time is not affected by the error, wich means, that the clock displays the real time. NTP (Net Time Protocol) is also working without any problems. So there are to reasons, for the error left: The first would be, that theres an error with an api, that should send the time & date to the applications, or theres an error in the ram. Anything that needs to get used fast, like the date, is saved @ the ram.

Normally, the OS writes the date in to the ram, during the booting-process, so it would be possible, that the os just wrote the false date into the random access memory. But I don’t think so, because the date, of the lower levels of the os, is correct.

On a website, I found the information, that rewriting (has to be done in sudo, but carefully, a false date-formate could damage the system) the date (using the terminal), would reduce the problem.

So I tried it on my iMac and it worked.

After resetting the date and a restart, the error never appeared again. Due to the fix, it is possible, that there was an error with rewriting the date, from the os level, to an for the applications accessible area. Fortunately, there is no permanent damage due to the defect.

More information about problems, with reading & writing to the ram: 

This error, is not a big thing, it`s just funny and not dangerous.

About the author of this article:

My name is Severin Kaempfer, I`m a code loving trekkie and nerd, that is just finishing his last year of school. In this summer, I`m going to start an apprenticeship as programmer.

Only execute sudo commands if you are familiar with computers.

No guarantee for the correctness of this article, I am not responsible for any damage.