During our closing flag ceremony at every camp I went to, we always sang at least the first verse of Taps (also sometimes known as Day is Done. It sometimes turned into an obscure trivia contest to find someone who actually knew the second verse. Since my Girl Scout leader was a life-long scout herself, she made sure we knew it. There are actually many different versions of Taps floating around, as evidence by reading the Taps Wikipedia Article.
Day is done, gone the sun
From the lakes, from the hill, from the sky.
All is well, safely rest, God is nigh.
Thanks and praise for our days
‘Neath the sun, ‘neath the stars, ‘neath the sky.
As we go, this we know, God is nigh.