It’s a curious business, this nonchalance about dates in Indian Philosophy. Swami Sadchidanandendra Saraswati in his discussion of the text Ista Siddhi of Vimuktatman Acarya neglects to mention his historical background, when he flourished or where he came from. I can now tell you that he flourished between 850 and 1050 A.D. or thereabouts. You may well say that this is a result of a career move into a no career, sanyas. Personal history is eliminated. We are now in the absolute present in the presence of the absolute. Doctrines flow and ebb and what Sri S.S.S. is concerned with is the moola avidya novelty proposed by Vimuktatman which is obviously later in planet side time that Shankara’s advaita. What more do you need to know?