Actually, it was chosen because ancient church leaders surmised that 30 shopping days were needed between Thanksgiving and Christmas.
Hmmmm...you might be onto something here.
May have to be re-thunk with more days added, what with Black Friday, Cyber Monday, the two day Green Monday, Trample the Wounded Hurdle the Dead Store Buster Days, etc.
Can't have too much oddly shaped, multicolored, made in China plastic crap, you know?