One of the central preoccupations of modern biblical scholarship has been the dating of individual texts to particular historical situations or relative to other texts, as well as reconstructing their diachronic development from earlier stages to the final forms that appear in various text traditions/translations (LXX, Qumran, MT). And while I think this is a worthwhile endeavor and ultimately necessary to explain the complex literary quality of the Bible, too often hypotheses have been advanced based merely on vague historical correlation, the desire to find kernels of great antiquity, and the assumption that biblical scribes were for the most part simply editors or tradents handing down earlier tradition. At the same time, the traditional dating of biblical texts has tended to lack engagement with holistic literary and ideological analyses or fail to entertain the possibility that the scribes responsible for large-scale compositions were simply inventors of tradition.
I have a lot more I could say about this, but in the interest of encouraging more methodological rigor and self-criticism in the dating of biblical texts I thought I would offer a few basic guidelines:
1) The burden of proof is on those who would date a text earlier than its surrounding literary context;
2) Such proposals also move on a sliding scale, the earlier one dates a text relative to the major contexts for the production of the Bible (Persian and Hellenistic periods, late Judahite monarchy) the more speculative and tenuous the argument becomes;
3) To demonstrate literary discontinuity requires a higher bar of evidence than continuity, i.e. on principle readings that make sense of the text at a synchronic level are to be preferred over diachronic readings.