Thanks for this it actually might help to clarify the Enoch calendar and its link to Genesis 7,8.
Interestingly the 150 days do work out with the Jewish luni-solar calendar. Not every year but frequently enough to notice.
That is why I have started to consider it again above the Enoch calendar.
Shalom
The problem with Genesis 7-8 is the usage of yod-mem for a yom in Genesis 7:11, 8:4, and 8:14. The reason this is done is probably because of the opening creation account where yam in the plural is yamim, typically rendered as seas, but yamim is also a plural form of yom: and therefore the yamim of creation can also be likened to an immersion as we find also the mention of the word mikweh for the gathering of the waters for the yamim. In other words it appears to be a play on words in the flood account in order to hide a secret.
However the original Hebrew Ashuri script, from the time of Ezra, was not separated, and was rather written in a form similar to the scriptio continua of the Greek Uncial texts. In the original Ashuri script the waw/vav also doubled up as a word separator, and was sometimes read as a particle of continuance and sometimes not read at all, (perhaps even sometimes serving as punctuation, like a full stop, colon, semicolon, etc.,). Moreover the final-form letters or sofits are also not original to the Ashuri script but became necessary when the text was separated and they began to drop the waw/vav out of some places in the text where it wasn't read as part of the text. What we see at Qumran is probably somewhere near the beginning of this process of separating the text, (the great Isaiah Scroll being a good example as sofits began to be used).
Even Josephus in recounting the flood narrative seemingly disagrees with one of the verses mentioned above, where he states that the flood commenced with the twenty-seventh day of the month, (Genesis 7:11,(Josephus, Antiquities 1.81-82)), which clearly disagrees with the Hebrew text which we now have.
How can this be? There is a major clue hidden in the LXX, and it is hidden in the fact that the LXX reads all three verses in question to say the same as far as the day of the month, that is, the twenty-seventh of the month in all three instances. Note that the LXX does not contain the word day in any of these three verses: that is because originally the full word yom, (yod-waw-mem), was not likely present in any of the verses, (or they would have surely rendered it into the Greek text: they were not sloppy with the Torah).
What this means is that it is highly likely that originally the text did not contain the word yom in any of these three instances, and the text was not separated, and each one read the text in the manner he saw fit, according to his own separation and understanding of the text: and therefore the abounding confusion concerning these three scripture statements in early writings such as Josephus and others.
So then, if you have a situation where the word written in the text appears to be asarim, and the text is not separated, but you have no word for day, (yom), you can read that as twenty, or as ten ym, with ym meaning something like yom, depending on how you choose to separate the text in your reading of it.
Here is what I am getting at:
בשבעהעשרים
How should we separate the above script?
There are two primary ways:
בשבעה עשרים ~ in the twenty-seventh
בשבעה עשר ים ~ in the seventeenth yam (for a yom)
There is also the possibility that there was originally a waw/vav between asar and ym, which might also be confusing to the reader or scribe who did not recognize or realize the potential that yam, (yod-mem), might be in reference to the seven yamim of creation. In short, I believe the LXX rendering of these three statements, Genesis 7:11, Genesis 8:4, and Genesis 8:14, tells us what was in the majority of the original Hebrew texts they had at their disposal. However the LXX unfortunately does not separate asar from yam, and therefore, (mistakenly), reads all three texts to say the twenty-seventh of the month.