This brief introduction to the calendar explains some of the science and mathematics hazal likely used in establishing the calendar. I had come across a claim by those associated with perpetrating the bible codes hoax that attributed hazal’s knowledge of the average length of time between lunations to halakha le’Moshe mi’sinai. As is explained in the article, hazal (and ancient science) knew the average length between lunations to 6 decimal places. Today, modern science knows that quantity to 8 decimal places. The error introduced by not knowing the 7th and 8th decimal place will become impactful in about 5000 years, absent a simple fix by an intervening Sanhedrin. It seems obvious to me which brings more credence and loyalty to Torah, hazal, and our traditions.