Does Genesis Combine Two Flood Accounts?

I was puzzled by all the doublets in the chronology of the Genesis flood milestones, such as this one: “Noah was six hundred years old when the floodwaters came on the earth” (Genesis 7:6), and “In the six hundredth year of Noah’s life, on the seventeenth day of the second month—on that day all the springs of the great deep burst forth, and the floodgates of the heavens were opened” (Genesis 7:11).

Why are two seemingly different dates (different by apparently 46 days) given? Were two flood accounts combined into one?  

The Genesis flood story recorded in Genesis 6–9 has been the subject of considerable debate among Bible scholars for centuries. Most scholars, including those at Reasons to Believe (RTB), have interpreted Genesis 6–9 from the perspective of a single calendar. Here, I offer a two-calendar interpretation, an explanation that incorporates a known cultural flood account and serves as a polemic against mythological explanations.

My solution starts by recognizing that doublets are a standard biblical device. For example, consider Jacob’s blessing: “Assemble and listen, sons of Jacob; listen to your father Israel” (Genesis 49:2–28).

My solution to the doublet puzzle, in Table 1 below, resolves the Genesis flood into two parallel accounts, one according to the Egyptian civil calendar and the other according to the Mesopotamian lunar calendar. I suggest that Moses, considered the author of Genesis by conservative scholars, created the doublets at least in part to facilitate the transition from the civil to the lunar calendar in the Genesis chronology.

Table 1: Parallel Accounts of the Genesis Flood

DescriptionCivil calendar accountLunar calendar account
Noah is warned about the flood6:9–227:1–5
The flood starts, but Noah and family have already entered the ark7:6–10 (600th year)7:11–16 (17th day, 2nd month, 600th year)
Water rises, the ark floats7:177:18
Water covers the mountains7:197:20
Everything dies7:21–227:23
Water levels: high at 5th, low at 10th month from the start7:24 (150 days); 7:25–8:3 (150 more days)8:4 (17th day, 7th month); 8:5 (1st day, 10th month of the flood)
Noah’s bird flies to and fro8:6–7 (raven)8:8–12 (dove)
Exactly one year later, the ground is dry again8:13 (1st day, 1st month, 601st year)8:14 (27th day, 2nd month)

Mesopotamian Flood Account
The Genesis flood is the same event, I suggest, as the flood of Atrahasis,1 the Eridu Genesis,2 the Babyloniaca of Berossus,3 and The Epic of Gilgamesh,4 which students in antiquity copied when learning cuneiform.5 Moses, as a New Kingdom Egyptian scribe exercising authority over Semitic people (Exodus 2:14), was almost certainly educated in cuneiform6 and would have known the Mesopotamian flood account.

In Gilgamesh XI.i-iv, Ut-napishtim was warned by his god Enki to build a great boat and place his family, friends, supplies, and animals in it. He did so and then the flood came. The flood prevailed seven days, killing all people and animals outside the boat. The gods wailed and starved. The boat then lodged on Mount Nimish, and the water receded seven days. At that point Ut-napishtim released in succession a dove, which returned to the boat, a swallow, which also returned, and a raven, which did not return, signaling the end of the flood. Ut-napishtim then put out a sacrifice to the gods. They came to smell his offering, but Ellil, the god who had brought the flood, was enraged that anyone had survived. Nevertheless, the other gods persuaded Ellil to immortalize Ut-napishtim and his wife. These stages of the Mesopotamian flood also correspond to the description column of table 1, albeit with different durations.

Parallel Biblical Flood Accounts
The flood chronology doublets form two parallel accounts that are each similar to the Mesopotamian flood account.

The civil calendar had twelve 30-day months plus five epagomenal (inserted) days. These months were not synchronized with the lunar months. The antediluvian chronology uses this 365 day calendar7 while the postdiluvian chronology and the rest of the Bible use the lunar calendar. “The first day of the first month of Noah’s 601st year” (Genesis 8:13) is thus the equivalent of “January 1, 601”: it means precisely the first day of the year and is not a reference to the phase of the moon. That this is the first day after the flood is shown by the use of the Hebrew harev (dry). Everything on dry (harev) land died in Genesis 7:22 but in Genesis 8:13 the land is harev again, meaning that the previous state of affairs has been restored.

The lunar calendar is based on twelve lunar months, on average 29.53 days. (The lunar calendar is synchronized to the solar year by inserting a thirteenth month seven times every nineteen years, the so-called Metonic cycle.) Counting from the seventeenth day of the second month of Noah’s 600th year to the twenty-seventh day (thus, 11 days) of the second month of his 601st year gives 12×29.53+11=365.36 days, making it the day after a year of 365 days, just like Genesis 8:13. During the flood, the two markers of water level, after one and two weeks in Gilgamesh, are seen in the civil calendar version at five and ten 30-day months, counted off in groups of 150 days (Genesis 7:24; 8:3). The lunar calendar versions of these two water level markers occur at the fifth lunar month of the flood and, I suggest, at the tenth lunar month of the flood (Genesis 8:4–5). Finally, in Gilgamesh the gods are starving after the first week of the flood. According to Genesis 8:1, precisely when the gods are panicking, the LORD is firmly in control.

The main chronological differences between the Mesopotamian and Genesis flood accounts are (1) the approximately two weeks allotted to the Mesopotamian flood versus the full year of the Genesis flood, and (2) Noah’s supposed fifty-seven-day wait in Genesis for the harev land to dry even more, versus Ut-napishtim’s immediate sacrifice when his bird failed to return. The wait in the ark disappears in my solution. If there is no waiting in the ark (the land is harev or dry again), Noah offers a sacrifice directly when his bird did not return to the ark, just like Ut-napishtim!

Why does the Genesis flood last exactly a year? I believe this is due to the Genesis chronological convention: integer math (whole numbers only; no fractions or decimals) means every chronological event is deemed to occur at the beginning of the year. Showing the beginning and end of the flood in both calendars also ensures chronological continuity. This continuity contrasts with the Mesopotamian flood chronology. According to the cuneiform text WB 444, written c. 1800 BC,8 kingship, and hence chronology, descended from heaven for the first king, but had to descend again after the flood. Instead of an integer number of years, the first postdiluvian dynasty lasts 24,510 years, 3 months, and 3.5 days!9 This is a chronological discontinuity reflective of the disarray among the gods. In Genesis there is no discontinuity. Rather, its two overlapping, full-year flood chronologies create a smooth transition from the old, civil calendar to the new, lunar calendar.

Theological Implications
Moses had sound reasons for making his flood chronology differ from that of Gilgamesh, one of which was to integrate the flood into the continuous chronology of the world from creation until the death of Joseph. The flood was a nonmythological part of real history, but was being taught in Mesopotamian accounts in a way that misrepresented the nature and purposes of God. Moses combined a deep knowledge of the science and literature of his day with a faith in the LORD’s serene rule of the cosmos to write an inspired account simple enough to teach the young and subtle enough to perplex the learned.


  1. Stephanie Dalley, trans, Myths from Mesopotamia: Creation, the Flood, Gilgamesh and Others, rev. ed. (Oxford: Oxford University Press, 1989), 29–35.
  2. Thorkild Jacobsen, “The Eridu Genesis,” Journal of Biblical Literature 100, no. 4 (December 1, 1981): 513–29, 524, doi:10.2307/3266116.
  3. The Chronography of George Synkellos, translated with an introduction and notes by William Adler and Paul Tuffin (Oxford: Oxford University Press, 2002), 40–41.
  4. Dalley, Myths from Mesopotamia, 109–115.
  5. Irving L. Finkel, The Ark before Noah: Decoding the Story of the Flood (London: Hodder & Stoughton, 2014), 254.
  6. William L. Moran, The Amarna Letters (Baltimore: Johns Hopkins University Press, 2002), xviii.
  7. U. Cassuto, A Commentary on the Book of Genesis, Part I: from Adam to Noah (1944), trans. Israel Abrahams (Jerusalem: The Magnes Press, 1961), 261.
  8. Stephen Langdon, The Weld-Blundell Collection, vol. 2, Historical Inscriptions, Containing Principally the Chronological Prism (London: Oxford University Press, 1923), 8–9.
  9. Langdon, The Weld-Blundell Collection, 11.