Moon situation for Shawwal 2007 in Miami Florida:
Oct 11th. Moon is too close to the sun to be visible at sunset at 6:57 pm. No chances of visibility.
Oct 12th. Moon, at sunset at 6:56 pm.
Bukhari Volume 3, Book 31, Number 133: Narrated Abu Huraira: The Prophet or Abu-l-Qasim said, "Start fasting on seeing the crescent (of Shawwal), and give up fasting on seeing the crescent (of Shawwal), and if the sky is overcast (and you cannot see it), complete thirty days of Sha'ban."