The deluge began on the twenty-seventh day of the second month, and the ark ran aground on the twenty-seventh day of the seventh month. The total is five months. The text also says the time was 150 days. That would make each month 30 days long. With the moon cycle repeating every 29.5 days, the months usually alternate between 29 and 30 days. What is going on here? There are a few possibilities, and we will go through each one.
The first possibility is a theory and cannot be proven. It fits nicely to fill the gap, and we don’t have to think about the disparity anymore. Ok, maybe that’s too harsh. It could be true.
Here it is. Before the deluge, the moon cycle was 30 days. Therefore, every month was 30 days. Noah counted 150 days because five 30-day months would equal 150 days. The deluge was cataclysmic. The earth tilted, the moon’s orbit shifted, and the cycle of the moon’s rotation slowed. And that is why it’s only 29.5 days now.
Theoretically, the whole earth was a temperate zone before the flood. The earth’s tilt is what gives us the seasons we know today. If the deluge resulted in the axial tilt, it would explain why the various climates exist. And if all of that is possible, then it is also possible that the moon’s cycle has slowed down.
Let’s look at the next possibility. Noah was using the Enoch calendar. I can’t tell you too much about the calendar because the version of Enoch that is in the translation of the Septuagint that I have, does not contain that section of Enoch. What I do know, I learned from people who follow the Enoch calendar. In a nutshell, every month is 30 days. Every season begins (or ends, I can’t remember) with one extra day. Therefore, each of the four seasons contains 91 days, and a full year is 364 days. That would account for Noah counting five months with 30 days each. But there’s a problem.
The Enoch calendar, I’m told, also follows the moon cycle. But the moon cycle is still 29.5 days. In just two months, the Enoch calendar would be off of the moon cycle. Adding in one day every season would move away from the moon cycle again. By the end of the year, the Enoch calendar would be off the moon cycle by 10 to 11 days, and there is no way to reconcile it. The only way for the Enoch calendar to work is if the first theory were also correct. But that still doesn’t account for the extra day every season. And let’s not forget, 364 days a year is 1.25 days a year too short. The Enoch calendar would be off of the solar cycle, as well. So now, the first theory would have to include the earth’s revolution around the sun slowing down after the flood, too. That’s a lot of things that have to be assumed to account for the 150 days that Noah counted.
Here’s the final and more plausible explanation. In the first post on days and months for the first Torah Portion, I explained how to watch the moon to determine the conjunction. You can re-read it here.
The deluge started toward the end of the second month. If the rain lasted for 40 days, the weather would have prevented observance of the moon. The third and fourth months would automatically begin after 30 days. The text says that Noah opened the window after they came to rest. That means that after the rain had stopped, Noah was still locked inside the ark and couldn’t see the moonrise. He still couldn’t verify the conjunction. Every other month of the 150 days would begin after the previous month counted 30 days. This procedure would put the calendar off the moon cycle by a few days, but verifying the next conjunction would put things back on track.
This method not only explains how five months could equal 150 days, but it’s the same method for determining the start of a month today. There’s no need to speculate about how things were before the flood.