Lifespan 1000 years to 80?

[Drich]

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.

Before the middle kingdom of Egypt there is only speculation. The Jewish calender did not start till after they became a nation at the end of the middle kingdom. Before then, before the First great Egyptian kingdom Years were based on celestial events (certain positions of constellations) or seasonal/harvest events. (in which case there were only three seasons, Birth/planting, Harvest, and death/the time when nothing grew.) If this were the case and harvest cycles were counted then a drought that could have lasted several years for us would only be counted one year for them. where as a year with lots of rain and good weather till late in the season could be counted several times as it may have yielded several harvests.

Our calendar is based on orbital position. In a time and place where those terms were meaningless the counting of the year was based on food production, or celestial worship. They did not count days because then it was thought the earth was the center and the sun move around it.

The point being a year then was not 365 1/4 days. So to count a year then as you do now makes you a fool.