When did Moses write Genesis?

The Book of Genesis is traditionally attributed to Moses, writing around 1400 BCE. However, scholars now say that the Book of Genesis was really written in stages over a period of several centuries during the first millennium BCE.

One of the contributors to Genesis was an anonymous author, now known as the Yahwist, who wrote during the eighth or ninth century BCE and provided material from the perspective of the southern kingdom of Judah. Another anonymous early contributor wrote during the eighth century BCE, providing material from the perspective of the northern kingdom of Israel, and is now known as the Elohist. The two traditions were combined by the 'JE Redactor' probably soon after the destruction of Israel in 722 BCE. The last major contributor to Genesis was the Priestly Source, writing during the sixth-century-BCE Babylonian Exile. The Book of Genesis, more or less as we know it today, was completed by the Redactor soon after the Return from Exile.