Lifespan 1000 years to 80?

[TubbyTubby]

What constitutes a Year, now?

What constituted a year before Gregorian calendar, before the Roman, before the Grecian, before the Hebrew calendar?

What constituted a "year" when Adam was alive?

No idea gorge, if you're suggesting the length of a year was different 6000 years ago then you tell me what it actually was.