On which day of the second month does Genesis say the Flood begins?

Genesis says the Flood begins on the 17th day of the second month.

Genesis 7:11 gives the date as the seventeenth day of the second month in Noah’s 600th year. It also describes the bursting of the great deep and the opening of the sky, marking the start of the catastrophic flooding.

The date is part of Genesis’s unusually detailed chronology. Later in the narrative, the Ark comes to rest on the mountains of Ararat on the seventeenth day of the seventh month, exactly five months after the Flood begins according to the story’s calendar.

Readers may confuse this date with the seventh day, when Noah and the animals had entered the Ark, or with the date when the Ark came to rest. Those are separate chronological markers in Genesis 7 and 8.