This gets asked occasionally, and the last time I saw it asked someone "answered" by just linking to a whole bunch of other threads and not commenting at all. I sense that was done more to passive-aggressively demonstrate that the question has been asked before than to actually help out, especially since most of the links either didn't contain answers or only linked to another thread that did. In an attempt to do better than that person I have gone through their list, and did my own search, and gathered links that have helpful answers within.
https://www.reddit.com/r/AskHistorians/comments/59mnjb/how_far_back_in_time_would_i_have_to_travel/