Dusk by Uri Shulevitz
I borrowed this from the library after seeing it on a list of best children's books of the year. Dusk was my least favorite time of the day as a kid. It always struck me as, kind of, a set up. We'd go back out to play after dinner and my mother would always tell us to come in at 'dusk.' Of course, you never recognize dusk until it's over.
In Shulevitz's Dusk a little boy, his grandfather and his dog go out for a walk. They watch the sunset and see the change over from dusk to dark. As the natural light fades, the city lights come up, revealing all the people rushing around and the different, festive ways they celebrate the holiday season.
Shulevitz highlights nature's beautiful light shows, and then let's the man made lights showcase all the wonder and joy of the season.