Saw this at breakfast early one morning in DC on our April vacation:

Here’s the key part, amped up for readability:

I’m sure the manager’s three-ring binder has a whole section about the alarm system, its care & feeding, and the importance thereof. I’d guess there’s a dead battery in there somewhere and a power failure in the recent past.
This ooops obviously doesn’t matter, right up to the point where they have a break-in and the alarm system timestamps the event incorrectly.
The camera peered through a pair of window panes across the entranceway, as I didn’t want to get too conspicuous… we were, after all, in DC.