In terms of “real world” time best estimates
Antiquity: 4000 BC-400 AD
Crisis: 400-800
Discovery:800-1750
Crisis:1750-1800
Modern:1800-1970?2000?
Each Era is 200 turns Maximum (if players accomplish things during the era it speeds up (but almost certainly not to less than 100 turns). I imagine the Crisis periods may have flexible dates:turn connections to help keep the pacing matching
Antiquity: 4000 BC-400 AD
Crisis: 400-800
Discovery:800-1750
Crisis:1750-1800
Modern:1800-1970?2000?
Each Era is 200 turns Maximum (if players accomplish things during the era it speeds up (but almost certainly not to less than 100 turns). I imagine the Crisis periods may have flexible dates:turn connections to help keep the pacing matching