What's the noun for sundown? Here's the word you're looking for.
sundowner
(Australia, obsolete) An itinerant worker, such as a swagman, who arrives at a farm too late in the day to do any work, but readily accepts food and lodging.
(Australia, obsolete) An itinerant worker, a swagman.
(nautical) A sea captain who shows harsh discipline by requiring all hands to be on board by sundown.
(medicine) A patient, usually demented, who tends to become agitated in the evening.
“Impaired judgment and sundowning (increased confusion when orienting cues diminish at night) often makes it necessary to restrict and protect the delirious patient.”