Assalam-o-Alaikum, What Islam says about the prophecies of Nostradamus? What Islam says about the doomsday on Dec 21, 2012 predicted by Nostradamus , Maya religion and also NASA verifies it on the basis of physics in relation to practically increase in the temperature of earth.
The knowledge of Qiyamah, i.e., commencement of it is known only to Allah the Most Exalted and none else and Prophet Muhammad ﷺ Nabi Sallalahu Alaihi wa Sallam has given some identifications before its advent. Some of which are experienced and some are yet to as is explained in details in Books of Ahadees e Mubaraka.
As for Nostradamus, he has not defined a date for the commencement of Qiyamath and even if defines yet there is no credence on it. It is necessary to refrain from thinking him to be correct or acting upon his sayings.
Allah knows best.