The phrase "midnight sun" refers to a natural phenomenon that occurs in polar regions during the summer months. It means that the sun remains visible in the sky even at midnight, creating a continuous daylight experience. Full definition
He was a cheerful and helpful guy to hang out with at camp during those magnificent 24 - hour days of midnight sun. (dotearth.blogs.nytimes.com)
(What makes this situation particularly appealing is that the eclipse takes place at the end of the two - month - long midnight sun). (scientificamerican.com)
Open Road Films will release Speer's Midnight Sun in theaters everywhere starting March 23rd, 2018 next year. (firstshowing.net)