A Biblical Year
A biblical year starts like a biblical day with light and new life, consequently in spring with the New Month of Abib (Aramaic / Syrian / Babylonian name 'Nisan'; modern March / April).
A calendar year (was) not 370 days long as the Masoretic (Hebrew OT) text suggests through the Flood account, but exactly 360 days divided into 12 months of 30 days each, as the Greek Old Testament proves through the correct Flood dates (the Flood began with Gen 7:10-12 and ended with Gen 8:14-16, from 27/02 until 27/02, not from 27/01 until 27/02 as per Masoretic texts).
Flood dates, Abib (Nisan) 27th vs. Abib 17th
Gen 7:11 (Greek OT) reads: "In the six hundredth year in the life of Noah, during the second month, on the twenty-seventh of the month, on this day all the springs of the deeps burst forth, and the waterfalls of the heaven were opened". The manipulation of Gen 7:11 (Hebrew OT) reads: "In the six hundredth year of Noah's life, in the second month, on the seventeenth day of the month, on the same day all the fountains of the great deep burst open, and the floodgates of the sky were opened."
Gen 8:4 (Greek OT) reads: "The ark ran aground in the seventh month on the twenty-seventh day of the month on the Ararat mountains". The manipulation of Gen 8:4 (Hebrew OT) reads: "In the seventh month, on the seventeenth day of the month, the ark rested upon the mountains of Ararat."
> The fact that both texts of Gen 8:14 coincide again in the 27th of the first month of the following year, makes it clear that the Greek Old Testament resulting in exactly 360 days of a biblical year are superior to the difference of 370 days in the Masoretic texts (see Rev 11:3 and Rev 13:5 below for the proof of the biblical 360-day-year). While the Genealogies had been manipulated in order to distract from the Messianic prophecy, no reason has been found so far for the manipulation of the flood dates.
360 days are also clearly proven through the specification in the Book of Revelation (1260 days / 42 months = 30 days).
"And I will grant authority to my two witnesses, and they will prophesy for one thousand two hundred sixty days [1260 / 3.5 years = 360 days] ..." Rev 11:3
"... speaking great things and blasphemies, and authority to act was given to him for forty-two months [42 x 30 =1260 days (3.5 years)]." Rev 13:5
It can be concluded with a reasonable certainty that even the constellations of the sun, moon and earth slightly changed through the Flood (significantly different height of mountains and of the sea level causing a minor change in gravitation), as we know by the different length of a solar year and lunar month (365 days and 29.5 days), compared to the original 360 days and 30 days.
THEOS created the world in a perfect balance with one language, but human sin brought unbalance, brought physical, spiritual and geographical separation and many languages. More details are found in the study 'The Flood'.
The following studies include more details about a Biblical Year: