The recent discussion about why history is now measured exactly as it was in the time of Christian historians, with just the labels altered to sound less religious, has another dimension. In fairness the historians deciding on how to label their dating faced the dauntingness of the unmeasurable and the human intellect does it's best to avoid that vista of the unfathomable. In this instance I am referring to the fact that numbering has to start someplace, and there is NO convenient place in a world accustomed to being able to start numbering with a definite historical event. The grand appeal of 1 AD is that it was nailed into (not a wood crossbeam but) a definable event. Now that this starting place is less obvious, where would the numbering start? It occurs to me that maybe 6000 BCE, which is reported to be about the time human writing started. But of course this is a convention too, and hardly less speculative than the recently popular system. And then we would have the clumsiness of some events being counted backwards from 6000 BCE. You do need an edge, even though the point which I would like to highlight is that there IS no edge to count from, not really.
Which brings up the extent the human intellect will go to to avoid realizing how mythical edges really are. That might be our next question.