New moons, different risings of the moon, and astronomical calculations

Question: We are accustomed to fasting the month of Ramadaan as thirty days, not less.

Answer: This is a wrong and Munkar (that which is unacceptable or disapproved of by Islamic law and Muslims of sound intellect) act because it is in disagreement with the commands of the Book of Allaah, Sunnah (whatever is reported from the Prophet Muhammad) of His Messenger Muhammad (peace be upon him), and the regular practice of his Sahaabah (Companions) and the Taabi`oon (Followers, the generation after the Companions of the Prophet Muhammad) (may Allaah be pleased with them all). This is based on the Aayah (Qur’anic verse) in which Allaah (Glorified be He) says… read more here.