The Hebrew word most often translated as “month” in the Tanakh (Old Testament) is “chodesh” (H2320), and it is always used when a date is given. Scripture clearly states there are 12 chodesh in a year, but only infers there are 30 days in each chodesh. We see this first in the Genesis account of the flood.
The Flood
In the six hundredth year of Noah’s life, in the second month (chodesh), on the seventeenth day of the month (chodesh), on that day all the fountains of the great deep burst forth, and the windows of the heavens were opened. And rain fell upon the earth forty days and forty nights.
The flood continued forty days on the earth. The waters increased and bore up the ark, and it rose high above the earth. The waters prevailed and increased greatly on the earth, and the ark floated on the face of the waters. And the waters prevailed so mightily on the earth that all the high mountains under the whole heaven were covered. The waters prevailed above the mountains, covering them fifteen cubits deep. And all flesh died that moved on the earth, birds, livestock, beasts, all swarming creatures that swarm on the earth, and all mankind. Everything on the dry land in whose nostrils was the breath of life died. He blotted out every living thing that was on the face of the ground, man and animals and creeping things and birds of the heavens. They were blotted out from the earth. Only Noah was left, and those who were with him in the ark. And the waters prevailed on the earth 150 days.
But God remembered Noah and all the beasts and all the livestock that were with him in the ark. And God made a wind blow over the earth, and the waters subsided. The fountains of the deep and the windows of the heavens were closed, the rain from the heavens was restrained, and the waters receded from the earth continually. At the end of 150 days the waters had abated, and in the seventh month (chodesh), on the seventeenth day of the month (chodesh), the ark came to rest on the mountains of Ararat. (Gen 7:11-12, 17-24; 8:1-4 ESV)
If there are 150 days from the 17th day of the 2nd chodesh until the 17th day of the 7th chodesh, that is an average of 30 days per chodesh over five chodesh. The only other indication of how many days are in a month that I have found in Scripture are references to a future event. Continue reading