When I was younger I used to be a night owl. I even had a night job. But over time, I started to find that no matter when I went to bed, my eyes just popped open & stayed open earlier & earlier as the years passed. Now the seem to have stabilized at 5:30 AM. So I get to see that sunrise too, most of the time. My circadian rhythm just kind of reset itself
Gonna pick the Bronze Age ( I want to see those early inventions invented), the 1940's (<3 FDR, and my nation reinvented itself amidst war) and 100 years from now, long enough for "Wow what progress" but not long enough for "Are these still even people or what??".