There are three popularly known criteria adopted for Islamic Moon Sighting in America, Local Moon sighting, Global Moon Sighting and the Fixed Calendar based on scientific calculations. Local Moon sighting limits the sighting of the moon within the continental Americas i.e US, Canada and some parts of South America. Global Moon sighting technique takes into consideration moon sighing in any part of the world. So for example, if the moon is sighted in Saudi Arabia then the Mosques and Committees following the Global moon sighting would declare the start or end of the lunar Islamic month and then there is a scientific calendar where calculations are made based on astronomical and historical data.
Islamic Moon Sighting Controversy in America