From Adam

These are the ages men may have lived from Adam:
Adam130 years
Seth105 years
Enos90 years
Cainan70 years
Mahalaleel65 years
Jared162 years

These are the generations men may have been born from Adam (half their ages):
Adam60 years
Seth50 years
Enos45 years
Cainan35 years
Mahalaleel30 years
Jared80 years

These generations add up to 300 years to the birth of Enoch.
Genesis 5:23 "And all the days of Enoch were three hundred sixty and five years."
Genesis 5:21 "And Enoch lived sixty and five years, and begat Methuselah:"
Perhaps Enoch was born in the Sothis year 300, 3936 BC. Then counting generations back Adam would be born about 4558 BC. If Adam and Eve were using the duodecimal system, year 800 duodecimal is 1152 decimal. Thus 4548 BC may be the year of Adam's birth 1152 years after the first Sothis cycle in 5700 BC. This because 10 years may have been miscalculated in these generations and because July 17 may have begun the first Sothis cycle, thus the cycle must have been begun in 5700 BC to complete the cycle July 16 4236 BC when Sirius appeared before dawn.