Hindu scriptures are classified into two parts: shruti or śruti, meaning what has been heard and smriti, or smṛti, meaning what has been retained or remembered. The Vedas are classified under śruti.
The following list provides a somewhat common set of reconstructed dates for the terminus ante quem of Hindu texts, by title or genre. All dates here given ought to be regarded as roughly approximate, subject to further revision, and generally as relying for their validity on highly inferential methods and standards of evidence.
^Oberlies, Thomas (Die Religion des Rgveda, Wien, 1998, p. 155) gives an estimate of 1100 BCE for the youngest hymns in book 10. Estimates for a terminus post quem of the earliest hymns are more uncertain. Oberlies (p. 158) based on 'cumulative evidence' sets wide range of 1700–1100
^Van Buitenen; The Mahabharata Vol. 1; The Book of the Beginning. Introduction (Authorship and Date).
^Narayan, R.K. The Ramayana. Penguin Group, 2006, page xxiii: "The Indian epic, the Ramayana, dates back to 1500 BCE according to certain early scholars. Recent studies have brought it down to about the fourth century BCE."
^Trautmann 1971:185 "If the Kautilīya Arthaśāstra in its present form is not so old as it pretends, the śāstra itself is certainly old, predating the dharma smritis." Mabbett 1964 "The content of the text is consistent with authorship in about the third century, C.E., and raises some questions which must be answered if it is to be assigned to the fourth B.C.E. Against this must be set the verses naming and characterising Kautilya, and the references in later literature. What emerges is that there is no necessary incompatibility between the essential claims that Chanakya was responsible for the doctrines of the Arthaśāstra, and that the text we know is a product of the later time. These do not conflict. The work could have been written late on the basis of earlier teachings and writings. Sanskrit literature being so full of derivative, traditional and stratified material, this possibility is a priori strong. Those who favour the early date usually admit the probability of interpolations....Those who favour a later date usually admit the probability that the work draws on traditional material. The controversy is therefore spurious. It is entirely possible that the Mauryan Kautilya wrote an arthaśāstra and that a later editor rewrote his work, or compressed it, or compiled a text from the teachings of his school."
^B. K. Matilal "Perception. An Essay on Classical Indian Theories of Knowledge" (Oxford University Press, 1986), p. xiv.