Hi all,
I don’t even know what title I should give to this thread. I have this goal, and the last datapoint is the derailment from almost a week ago. And suddenly I have an eep day today…
If guessing what the reason might be were allowed, I would guess that jrrxraqf bss pbhyq or ohttl. But I don’t really know.
Anyway, is it only me or has anyone seen anything like this before?
I’m not sure I understand the question. Are you asking “How did my road get to having this odd looking shape?” or are you asking “Given my road, why didn’t I get more warning about my eep day?”
My answer to the former is “I have no idea / did you do this on purpose?”
My answer to the latter is: Non monotonic roads reveal some of the oddities of Beeminder’s “lane” concept. There’s a lot of talk about “lanes” and “if you’re in the right lane today you can’t derail tomorrow” but strictly speaking it’s all lies, hinging on a monotonicity assumption. The truth is that your “lane” is determined solely by your position relative to today’s road’s critical edge. So you will always go from green straight to red in a situation like this.
Apologies if you were interested in the former question and I’ve been no help whatsoever. 
Zooming in the graph, it looked to me like you retroratcheted it! I’ve removed the retroratchet(-esque) section of your road, but I’m not positive if that was something to do with weekends off or not, so I’ll leave reading the log to an expert.
It’s a combo problem of the auto-ratchet plus the weekends off setting. For a do less goal we use the weekend rate to schedule a jump in the road for the upcoming weekend, e.g. if you set a weekend buffer of 100 pages read, we’ll take the road and schedule in a +100 page jump on saturday, to give you that extra buffer. But we do that each week for the following saturday, and if your road changes in the meantime, the scheduled jump can actually wind up making the road non-monotonic…