Which makes me want to imagine historians 2000 years from now debating whether 9/11 really occurred on 9/11 or closer to 12/11. What might be a useful reason f

Which makes me want to imagine historians 2000 years from now debating whether 9/11 really occurred on 9/11 or closer to 12/11. What might be a useful reason for that, except academic exercise? Even being able to tell the exact year some 2000 years later would still be a very precise, all things considered. For all practical purposes I can imagine, knowing the time of eruption rounded to "in the fall of year NNNN" would be more than enough. Maybe there is a genuine need for more precise dating but the need would have to be partially theoretical due to the fact that it's simply pretty damn difficult to tell. Based on the quoted part, we basically have some old stories and notes which themselves suggest something but still leave many doors open and that's all.