When I was a student (during 1978-79), I had a book on Ancient Indian History with chronological events (from Vedic times to Modern India), in which the author arrived at date of Ramayana some 7 lac years BC and Mahabharata about 4 lac years BC (I vaguely remember the dates) based on astrological calculations.
The best part of the book was it had listed out the chronology of events running into several pages, from Vedic times to Birth of independent India, with names of Kings / dynasties/lineage etc.
Another interesting part of the book is that it argued with proofs that the Indian King who fought Alexander the Great, was Chandra Gupta of the Gupta dynasty and not Chandra Gupta Maurya of the Mauryan dynasty.
I lost the book and am still searching for the book, but unable to find it online / in bookstalls. I don't remember the title of the book or author's name. Can some body help me with the name of the book and where I can find one?