The time of the reappearance of Imam Al-Mahdi [AS]is known to Al;ah. When he will reappear he will remove away all the injustice and the wrong and will establish justice all over the world. No doubt that the sinful acts of the believers can delay the reappearance,because they are supposed to be his followers and supporters and servants, and the reappearance need’s enough pious and obedient followers.
wasalam.