That was discussed over here, so I don’t think the possibility is very likely at all. The constellation of likelihoods supports a ca. 400 BCE date, plus or minus a couple decades or so.
Perhaps in these respects I can make fuzzy lines (for a chart, if one should end up being possible) & italicized phrases on the timeline to cover these outlier ideas, and then make a solid line & normal text to cover the more likely cases. Of course this chart will be altogether ‘fuzzy’ to some extent in any case, but at least we can try to tighten things up.
And, I’m not sure about the relevance of this “three vedas reference” (trayī vidyā?) you’re looking for. That would’ve been around 1900-1100 BCE, long before this timeline begins.
[quote=“Gabriel, post:12, topic:2832”]
Thanks for the link, but it doesn’t detail the sources…[/quote]
Sure it does, the whole paper reflects on previous attempts & their sources, and throughout builds up a discussion that ends with the linked conclusion.
Have a look at another paper, this one also providing a literature review & further resources:
A New Publication on the Date and Historiography of the Buddha’s Decease (“nirvāṇa”): A Review Article by D. Seyfort Ruegg in the Bulletin of the School of Oriental and African Studies, University of London, Vol. 62, No. 1 (1999), pp. 82-87.
The conclusion there is a date range of 420-350 BCE.
The Encyclopedia of Buddhism reviews the discussion as well, reporting similar conclusions overall.