Console: "Month 13 is out of bounds"
In the process of trying to figure out why my iMac shut down, I saw, in Console, a ton of entries, from many processes, that say "Month 13 is out of bounds." I'm not sure where my Mac got the idea it was in a month 13, but clearly it did, and a lot of tasks are having trouble with that.
Has anyone else seen this? I wonder if it's some kind of bug that got introduced.
IMAC (RETINA 5K, 27-INCH, LATE 2015), macOS Sierra (10.12.6), 3.2 GHz i5, 16GB RAM, 1TB Fusion Dr