According to Genesis, on what day of Noah’s life did the flood begin?

According to Genesis, the flood began on the seventeenth day of the second month of Noah’s six-hundredth year. Genesis 7:11 gives this date while describing the bursting of the fountains of the deep and the opening of the heavens.

This date is distinct from the length of the rainfall. Genesis also says that rain fell for forty days and forty nights, but the broader flood narrative tracks a much longer period of rising and receding waters.

Readers sometimes combine the different dates in the story. Genesis 8:4 gives another seventeenth-day date, when the Ark rested on the mountains of Ararat, but that occurs in the following year and the seventh month.