Around the summer solstice the sun just dips below the horizon and then pops right back up again. Around midnight or so it goes from daylight to a light twilight. Just as you are saying to yourself, "Gee, I guess I could go to bed now," the sky gets light again.
My son and daughter-in-law were visiting and very much enjoying the sky. I love sleeping with the sound of hermit thrushes calling all night. Note our middle-of-the-night wacky dress!