Calendar range (Gregorian):
05/04/4100 BC to
The BLC day starts at sunset Local Time on the Gregorian day.
Pre flood days are 365.2421896698/360=1.014561637x=20.98675726 minutes longer than post flood days.
BFG = Before Flood Gregorian with no leap years and 26 days in December (making 360 days to the year).
Day length changes at sunset (18:00) on 2370April5 BC, the start of 2371Nisan1.