Sundowning?
Many dementia patients suffer from what is called sundowning.
Sundowning, or sundown syndrome,[1] is a neurological phenomenon associated with increased confusion and restlessness in patients with delirium or some form of dementia. Most commonly associated with Alzheimer’s disease, but also found in those with other forms of dementia, the term “sundowning” was coined due to the timing of the patient’s confusion. For patients with sundowning syndrome, a multitude of behavioral problems begin to occur in the evening or while the sun is setting.
https://en.m.wikipedia.org/wiki/Sundowning
Dementia patients become agitated in the evening between 6 and 9pm. They can be sweet as pie the rest of the day, but when sundowning kicks in, they can be short-tempered, agitated, restless ... and for lack of a better word, just crazy.