[prewett]

What other notion of year would people use? There's clearly a repeating cycle of that takes approximately 360 days. The seasons cycle, the stars come back to their same spots. I don't think there is any evidence that ancient people used a different version of year. In fact, given that we still have Babylonian influences like 360 degrees in our circle, I'd argue that we have continued in their tradition.

[strken]

Someone on the equator might divide the orbit of the Earth around the sun into two halves, a north-sun "year" and a south-sun "year".

I have absolutely no evidence that any group did so, of course, but it wouldn't be totally absurd.