Biblical Metonic Cycles
A Metonic Cycle is 19 years so that
4 x 19 = 76 years
Below are Metonic and Eclipse Calendric Cycles
in the Chronology of the Old Testament
and similar calendric cycles in Aztec and Maya calendration

Adam to Jared - 6 Patriarchs 12 Metonic Cycles of 76-years The sum of ages of the 6 Patriarchs from Adam to Jared is 5514, a sum which is exactly divisible by 6 to give 919 (this is 76 x 12 = 912, + 7 intercalations). Enoch is the "year" at 365, and the Book of Enoch - wrongly excluded from the Bible - is in fact the Biblical book of calendration. The seven normal intercalations in the Metonic system for the first 7 Patriarchs from Adam made Enoch his own Jubilee. The Babylonians similarly intercalated in the 3rd, 6th, 8th, 11th, 14th, 17th and 19th years of the Metonic cycle, i.e. they also used 7 intercalations.

912 30-day months = 76 360-day years Methuselah to Joseph = 16 Patriarchs 912 x 30-day schematic months gives a sum of 27360 days, which, divided by 76 is the schematic year of 360. From Methuselah to Joseph the sum of ages of 16 Patriarchs is 6304 years, divisible by 16 to give 394. Why? This schematic period corresponds to the Callippic period of 27759 days of Callipus of Cyzicus, i.e. 940 lunar months of 29.53 days = 27759 days, which is 441 hollow months of 29 days and 499 full months of 30 days. In Greece, Meton used 440 hollow and 500 full months. To the right, we see that the Bible had a similar system using 394 hollow and 518 full months. It was all seen as a secret science. We have a system using 394 hollow (or defective) months of 29 days each. 394 minus 365 = 29 days 394 x 29 days = 11426 days 912 minus 394 = 518 full months. 518 x 30 days = 15540 days 11426 + 15540 = 26966 days = which is 394 days LESS than 27360 days, i.e. 912 30-day schematic months, so that 912 30-day months = 394 29-day months + 518 30-day months plus 394.

Manetho, Pandorus and the Discovery of Patrick Ryan
The lists of Manetho and Pandorus, from Budge's Book of Kings,
show that Pandorus thought that Manetho's "years" meant "months".

 

THE SUM OF 969 is SIGNIFICANT
FOR CALENDRATION
BIBLE
The sum of 969 is found for the age of Methuselah in the Bible. 969 is significant for long-term calendric calculation since it also a Metonic calendric multiple, as 51 x 19 Metonic Cycles = 969 and, further, 969 divided by 52 = 18.63, which is an eclipse cycle, as shown by Hawkins for the 56 Aubrey holes at Stonehenge.
MESOAMERICA
Hence just as 52 weeks marked the "year of days", so 52 years marked the "year of eclipses". This system was also used in Mesoamerica by the Aztecs and Maya as the Tonalpohualli, whereby two 52-year cycles were considered to be One Old Age "when the day cycle, the year, and the period of Venus all came together." See Encyclopaedia Britannica, Calendar, Macropaedia, Volume 15, 15th edition.