I can't believe I'm just figuring this out now.
I've got 89 pages left, and It just occurred to me what the moons and suns next to peoples' names mean. I feel so stupid, but it makes so much sense. For the longest time I had been trying to figure it out, but I'm glad I finally got it.
A sun denotes a Daytimer.
A moon denotes a Nighttimer.
I really like how Chuck labeled himself as a Nighttimer.