In Genesis's Noah's Ark story, on which day of the second month did the flood begin?

In Genesis's Noah's Ark story, the flood began on the seventeenth day of the second month.

Genesis 7:11 gives the date when the fountains of the deep burst open and the windows of heaven were opened. The same verse places the event in Noah's six hundredth year, making the date one of the narrative's most precise chronological details.

Genesis uses a sequence of dated milestones throughout the flood account. The ark came to rest on the seventeenth day of the seventh month, and the mountain tops became visible in the tenth month. These dates help readers follow the changing water level.

This date should not be confused with the date Noah and his family entered the ark. Genesis 7:10 says the floodwaters came seven days after the entry instruction. The question asks for the flood's beginning date as given in Genesis.