Often offices that have late evening appointments or weekend appointments will take off a day during the week to balance out their work/life schedule.
Historically, in the small town I'm from, a lot of local business' would close on Thursdays. I'm not really sure why, maybe church on Wednesday nights would run late and everyone was tired the next day, who knows.
I would suggest calling one of the offices and asking.
Laura, CPC, CPMA, CPC-I, CANPC, CEMC